# clear or clean



## P&B

When I was a a university student (some 20 years ago) one of my native teachers told me that although people say both:
"clear the blackboard" and "clean the blackboard"
the latter is not correct, because the blackboard is not dirty, we just want to remove what is wrtitten on it.
Similarly: we clear the table after eating and not clean the table (unless it is dirty).
I also learnt "clear criminal record" but I can see on the net (where I generally try to check if certain expressions / words are used) that "clean criminal record" is also used.

Would you guys agree that "clean" in the above mentioned examples is not correct (even if it is used)? Languages do live and change. I know many words and expressions in my mother tongue that were formerly condemned by our parents and are now widely used and accepted. There might be differences here in British and American usage.

Thanks for any comments!


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## PaulQ

I suspect your lecturer had his major degree in pedantry but from a minor university. I have never heard "clear the blackboard". You clear three-dimensional objects, that is why you *clear up* after you have been working, the *up *indicating "completely", and why you *clear *a table - you remove the items - you leave a clear/unobstructed surface. Cf "The place was deserted and the roads were clear." 
*
To clean* is associated with hygiene and/or the total removal/elimination and destruction of *unwanted *items and substances. Hence the writing on the blackboard is "unwanted" and you clean the writing off/from the blackboard.


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## Cenzontle

When you wipe away the writing, I would call that "to *erase *the blackboard".  The device made for that purpose is an eraser, a blackboard eraser, or a chalkboard eraser.
I, like PaulQ, have never heard of "clearing" a blackboard.
"Cleaning" a blackboard, for me, might mean washing it with a wet sponge, to remove the dust after it has been erased many times.


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## Parla

> I also learnt "clear criminal record" but I can see on the net (where I  generally try to check if certain expressions / words are used) that  "clean criminal record" is also used.


Is it used as a verb or an adjective? To remove an episode of wrongdoing from someone's record is to _clear_ it. The person thereafter has a _clean_ record.

"Clear the blackboard" does make sense to me, in the same sense that "clear the table" does. It's removing what's [written] on it, making room for other writing. Yes, that's accomplished by erasing it—although of course what's actually being erased is what's written on it, no?


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## dukaine

Concerning the criminal record, "clean" sounds better to me than "clear".  I can't think of a time I've ever heard "clear" in this context, although an English speaker will certainly understand you.


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## zaffy

I know water can be described as 'crystal clear'. What if I said "crystal clean"? Would it work at all or would it sound totally awkward? Well, actually, logic somehow tells me "clean" should be a better choice. Why do you say 'clear'?  What does it imply compared to 'clean'?


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## Keith Bradford

Although they might in practice come to the same thing, hold in mind the basic meaning of the two words:

Clear = free from obstructions, empty.
Clean = free from dirt, pure.


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## JulianStuart

zaffy said:


> I know water can be described as 'crystal clear'. What if I said "crystal clean"? Would it work at all or would it sound totally awkward? Well, actually, logic somehow tells me "clean" should be a better choice. Why do you say 'clear'?  What does it imply compared to 'clean'?


Crystals are typically clear* - not translucent or cloudy or dirty.  Water can be any of those but when it is very clear (and you can see through many metres, for example), we say it is crystal clear = as clear as a crystal

*In the meaning of transparent, not the meaning of colourless


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## dukaine

zaffy said:


> I know water can be described as 'crystal clear'. What if I said "crystal clean"? Would it work at all or would it sound totally awkward? Well, actually, logic somehow tells me "clean" should be a better choice. Why do you say 'clear'?  What does it imply compared to 'clean'?


I think "clear" implies you can see through it, like a crystal, so I think "clear" is more appropriate. "Crystal clean" sounds weird to me.


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## zaffy

Keith Bradford said:


> Although they might in practice come to the same thing, hold in mind the basic meaning of the two words:
> 
> Clear = free from obstructions, empty.
> Clean = free from dirt, pure.


That's why my Polish logic tells me 'clean' should be a better choice as for water. Such water is free from dirt, not free from obstructions.


dukaine said:


> I think "clear" implies you can see through it, like a crystal, so I think "clear" is more appropriate.





JulianStuart said:


> we say it is crystal clear = as clear as a crystal



I see, looks like languages have different logic. In Polish water might be 'clean' beacuse of lack of dirt. Or maybe it's just me, as we have one word for yours two, as usual.


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## heypresto

Crystal clear water will be clean and free from dirt, but 'crystal' refers to the _clarity _of it, and so we say 'crystal _clear_', not 'crystal clean'.


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## JulianStuart

zaffy said:


> I see, looks like languages have different logic. In Polish water might be 'clean' beacuse of lack of dirt.


Of course crystal _clear_ water can often also be described as _clean_ .  It's the word _crystal_ that means transaparent in the way that crystals are.  Water might have toxins dissolved in it or a low (invisinble) level of pathogens, either of which would make it unclean, even if it is crystal clear


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## zaffy

So these two work and make sense, right?

Scenario 1. A mum is wondering whether or not let her child go into the water, as there might be some pathogens. She is talking to her husband.
"Darling, is the water clean enough for Tom to go in and have  fun?"

Scenario 2. A group of scuba divers are talking.
"Hey, is the water clear enough today to go down as deep as 30 feet?"


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## Roxxxannne

They make sense to me.


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## JulianStuart

zaffy said:


> So these two work and make sense, right?
> 
> Scenario 1. A mum is wondering whether or not let her child go into the water, as there might be some pathogens. She is talking to her husband.
> "Darling, is the water clean enough for Tom to go in and have  fun?"
> 
> Scenario 2. A group of scuba divers are talking.
> "Hey, is the water clear enough today to go down as deep as 30 feet?"


Yes - one implies freedom from dirt and germs, while the second focuses in transparency.


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## zaffy

Another thing that bothers me is clear/clean vs. clear up/clean up. I mean there is a clear difference between the verbs 'clean' and 'clear', however there seems to be no difference between 'clear up' and 'clean up? So, am I right with these interpretations?

Can you clear your room? - (make your room empty or simply remove obstructions)
Can you clean your room? (make you room clean, remove all the dirt, wash the floor, etc)

Can you clean up your room? = Can you clear up your room? (make you room clean, remove all the dirt, wash the floor etc)


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## heypresto

Can you clean up your room? = Please make your room clean. I'm not sure if we'd say this rather than 'Please clean your room.'
Can you clear up your room?  = Please make your room tidy. Put your clothes/toys/games away where they should be.


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## Roxxxannne

I would not say "clear your room" if I wanted someone to get things out of the room.  I'd say "Get those things out of the room."
"Clean your room" sounds like I want the person to vacuum or sweep and wash the furniture and the floor.
"Clean up your room" is a succinct way of saying "Put away your toys and books and hang up your clothes unless they're dirty, in which case put them in the laundry basket.  And take that rug outside and shake it out.  There must be a whole bag of pretzels crumbled into it."

cross-posted


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## zaffy

Roxxxannne said:


> I would not say "clear your room" if I wanted someone to get things out of the room. I'd say "Get those things out of the room."



I see. How about this? 
"The painters are coming tomorrow. We need to clear the room. "

It conveys the idea of emtyping the room, but doesn't sound natural, right?


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## JulianStuart

zaffy said:


> I see. How about this?
> "The painters are coming tomorrow. We need to clear the room. "
> 
> It conveys the idea of emtyping the room, but doesn't sound natural, right?


It sounds just fine; in that context, people will understand that we (often) need to move everything, out especially if they are painting everything.


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## Roxxxannne

"We need to clear the room" sounds to me as though two police officers are talking about a bomb on a timer that's set to go off in five minutes in a room full of people.   They need to get everyone out of the room. 

In a situation with painters, I'd probably say "we need to get all the furniture out of the room."
If in that situation someone said "The painters are coming tomorrow, so we need to clear the room." I'd know what they meant from the context.  But it doesn't sound like ordinary colloquial American English. [Edited: at least not  my ordinary colloquial English ]
I can, though, imagine saying, "The painters are coming tomorrow.  We need to clear all this stuff out of the room."


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## zaffy

And say I'm taking with the painter on the phone and they ask me if they can start, i.e., whether or not the rooms are ready for the job. Can I say 'clear' or would you prefer 'empty'?

A: So can we start tomorrow? 
B: Absolutely, the rooms are clear. You can come any time.


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## Roxxxannne

I'd probably say 'the rooms are empty.' But "I cleared out the rooms' would work too.

This reminds me that if A wants to put her laptop on a table and B has strewn newspapers and books and papers covered with scribbled physics formulas all over the table, A might say, "Can you clear some of this table for me?"


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## zaffy

"I can hear you loud and clear"

Here, 'clear' means with no obstructions, right?


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## heypresto

Not really. It means 'with no distortion' or 'understandably'. Clearly. I can hear all the words you are saying.


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## zaffy

heypresto said:


> Clearly. I can hear all the words you are saying.


By obstructions I meant jams, for example.


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## heypresto

What do you mean by 'jams'?


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## zaffy

I made a noun from the verb "jam". But looks like it doesn't work 

_Foreign radio broadcasts were regularly jammed._


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## zaffy

And when our boots are covered with snow, do we 'clear' or 'clean' them off snow? Or either works?

_Clean the snow off your boots before you get in the car.
Clear the snow off your boots before you get in the car._


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## DonnyB

zaffy said:


> "I can hear you loud and clear"
> 
> Here, 'clear' means with no obstructions, right?





zaffy said:


> By obstructions I meant jams, for example.


No, it usually means with no atmospheric interference causing the transmission to fade or 'break up'.


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## zaffy

And how about the snow example in #29?


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## dukaine

zaffy said:


> I made a noun from the verb "jam". But looks like it doesn't work



It does work, heypresto just wanted specifics on what you had in mind ☺️


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## lingobingo

My two penn’orth as requested…

*Crystal clear*  is a common English phrase. There’s no such term as crystal clean . It would simply come across as either an error or a misguided attempt to change an idiom.

In my neck of the woods, we clean (or wipe, brush, etc.) snow off our boots. (Clean your boots before you bring them in here!  Clear your boots before you bring them in here! ) But people clear snow from the drive/driveway of their house.


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## zaffy

lingobingo said:


> In my neck of the woods, we clean (or wipe, brush, etc.) snow off our boots. (Clean your boots before you bring them in here!  Clear your boots before you bring them in here! ) But people clear snow from the drive/driveway of their house.



So "clear snow off boots" must be AE, right?


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## lingobingo

Or it could just be what one person chose to say in a very specific (outdoor) situation. The exact context governs what’s a natural way of saying something and what isn’t. This is a very different scenario from being asked not to step into a car with your boots covered in snow, or to clean your boots when you get home.


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## zaffy

And do you 'clean' or 'clear' snow off you car with a brush? I heard both.


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## lingobingo

I’d use *clear* in that case, as I think most people would. You’re not “cleaning” your car. You’re just getting rid of the snow in order to drive safely.


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## zaffy

And here, only 'clean' works, right?

_Mum, how can I clean ink off my desk? _


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## lingobingo

Yes.


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## zaffy

So, looks like 'clean' works with surface dirt only, while 'clear' refers to space, if you know what I mean. Snow takes up some 3D space, a ink stain takes up some flat surface space.


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## Roxxxannne

Some AmE speakers might use 'clear,' but if I had a choice between 'clear' and 'clean' for the removal of snow from my boots, I'd definitely use 'clean.'


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## Roxxxannne

I don't think it has to do with surfaces and spaces: to me it has to do with whether something is 'clutter' or 'dirt' in a sort of anthropological sense.


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## zaffy

Well, you can't imagine how helpful you guys are. Non-natives are lost. Dictionaries don't help at all. I guess the clean/clear difference was pretty clear to me until I started to figure out the 'clean snow off / clear snow off' examples. As here your logic stops working for me. And I find it weird that you "clean snow off shoes" while "clear snow off cars."  You generally "clear snow off roads" and some of you "clean snow off roads". 

Speaking of them being used as adjectives, there also seems to be some problem with logic. For us a table can be clean and in the same way our conscience can be clean. But looks like you prefer "clean" for literal dirt and "clear" for metaphoric dirt.


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## heypresto

zaffy said:


> And do you 'clean' or 'clear' snow off you car with a brush? I heard both.


I'd say you _brush _the snow off your car with a brush. And _clear _the snow from around your car.


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## Roxxxannne

zaffy said:


> For us a table can be clean and in the same way our conscience can be clean. But looks like you prefer "clean" for literal dirt and "clear" for metaphoric dirt.


I think the 'dirt' vs. 'clutter' distinction has to do with whether the stuff in question is in the wrong place or not.  I clear snow off my car's windshield but I clean snow off my boots when I come in the house.  If a car has been parked outside during a snowstorm, it's expected that snow will accumulate on it, and removing the snow is _clearing_ away something that is 'legitimately' there but in the way.   One expects to get snow on one's boots when one is outside in the snow, but when one goes inside a building or gets into a car, the snow is out of place, and therefore illegitimate or 'dirty', and so one _cleans _it off one's boots. (I am inaccurately riffing on the work of the social anthropologist Mary Douglas; see her book _Purity and Danger_, published in 1966)
But since I do not regard snow as out of place in my house, I avoid the lingiustic issue and just brush it off.


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## Packard

This came up in a conversation recently.  A friend said he "snow-blowed" his driveway, meaning he used a snowblower to clear off the snow.  

I mentioned that the "how" is not important, and a shovel, snowblower and snowplow all "clear away the snow".  

For the snow on cars, driveways, roadways, etc. I use "clear".

We used actual slate chalkboards when I was in school.  The teacher would use an eraser to clear out old writing but at the end of the day a "blackboard monitor" would use a sponge and water to "clean" the blackboard.

The green versions came later.  I understand that they use whiteboards in school now.


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## zaffy

And does antivirus software 'clean' or 'clear' computer systems?


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## Packard

I am finding "remove" when I do a google search and generally before they actually infect your computer

How Does Antivirus Work?

_An antivirus software works by *scanning incoming files or code that's being passed through your network traffic*. Companies who build this software compile an extensive database of already known viruses and malware and teach the software how to *detect, flag, and remove them.*_


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## zaffy

Yeah, but somtimes we want someone to take a look at our computer and remove all unnecesary or dangerous things. In Polish we would say "Could you please clean/clear (we have one verb) my computer as it's been slow recently". Which of them would you prefer in everyday language?


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## Packard

A google search shows several options, the first three pages I looked at generally favored "clean" and "remove".  However "clean" in the absence of context could easily mean the conventional usage, that is, to disinfect using chemicals or commercial cleaners like Lysol or bleach.


get rid of viruses
clean
wipeout viruses
remove viruses

how to clean your computer of viruses - Google Search


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## Roxxxannne

from How to Clean Up a Slow Performing Computer

*"How to Clean Up a Slow Performing Computer*
...
                        1                    Cleaning up the Disk on Windows                                     

                        2                    Cleaning up the Disk on Mac                                     
...

This wikiHow teaches you how to clean out old files, programs, and settings which cause your computer to slow down. ..."


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## Packard

I agree that "clean" and "remove" are the two most commonly used words for getting rid of viruses and malware.  But a Google search for "cleaning your laptop" yields this, with most of the references to using isopropyl alcohol and wiping cloths.  

So context is required for "clean" and "remove" invariably includes that context.

_How to remove viruses from your computer. _ (Adequate context)

_How to clean your computer. _(Not enough context)

cleaning your laptop - Google Search


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## Αγγελος

zaffy said:


> I know water can be described as 'crystal clear'. What if I said "crystal clean"? Would it work at all or would it sound totally awkward? Well, actually, logic somehow tells me "clean" should be a better choice. Why do you say 'clear'?  What does it imply compared to 'clean'?


In this particular context, 'clear' means 'transparent'.


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## Αγγελος

zaffy said:


> I made a noun from the verb "jam". But looks like it doesn't work
> 
> _Foreign radio broadcasts were regularly jammed._


 'Jamming' is deliberate, as in your example. Otherwise, what you are thinking of is normally called 'static' or 'interference'.


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## Αγγελος

To further complicate matters, let us also mention the verb 'to cleanse'. Usually used figuratively, as in "Thou shalt sprinkle me with hyssop, and I shall be cleansed " (Psalm 50, known to Catholics as _Asperges me_), but I suppose it can also be used with reference to toxins or pathogens.


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## Packard

And "cleanse" is also used by the detox-freaks for emptying the entire digestive system of all waste in an effort to detoxify their bodies.  There are health risks associated with this process.  

I only hear "cleanse" used within the scope of these detoxifying treatments; I am aware of the religious usage (but I don't come in contact with those who do use this term in that manner).


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