# je-li + instrumental case



## Stijn

Ajoh,

Thanks for the replies to my first topic.

I'm trying to decipher a Czech mathematics book that I bought last month in Prague. I have two questions regarding the sentence
"Dvě obecné rovnice přímky určují stejnou přímku, je-li jedna z těchto rovnic násobkem druhé."
Considering the context, this obviously means
"Two of the general line equations define the same line, if one of them is a multiple of the second."

1) The <verb>-li construction is used quite a lot in the book, but I haven't seen an explanation of it. When can you use it? Is it the common way of making an "if"-sentence?
2) The instrumental case of násobek -> násobkem surprises me. Why is it instrumental?

Děkuji,
Stijn


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## kelt

Hi,

the "verb-li" construction is a formal way how to express "if". This construction is used only in the written form and, as far as I remember, nobody would say it.

Nominative would be equally fine, instrumental could be slightly more formal/older.


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## Jana337

We have a dictionary entry and an old thread about -li. 

Instrumental: It is very common in sentences of the type "something is something". 
You can use the nominative if what you say is, so to speak, a permanent feature (or true by definition). The instrumental is used, more or less, for transitory states.
However, even with this theory in mind, you will often struggle to understand why we used the instrumental in a particular sentence. If it's any consolation, natives speakers often fail to reach a consensus as well, and sometimes both versions can be considered correct. 

Some examples: 
_Můj bratr je blonďák._ - His hair is naturally blond.
_Můj bratr je blonďákem._ 
_Můj bratr je učitelem matematiky._ - He is a math teacher but that need not last forever.
_Můj bratr je učitel matematiky._ - This one works and is common. The sentence above kind of says "currently, my brother..." whereas this one doesn't imply that his job could change.

Unlike Kelt, I would not really like the nominative case in your sentence about math.


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## winpoj

Jana337 said:


> You can use the nominative if what you say is, so to speak, a permanent feature (or true by definition). The instrumental is used, more or less, for transitory states.



I wonder, Jana, what you base this explanation on. It may be due to a gap in my knowledge, but I've always thought that the only difference between "je učitel matematiky" and "je učitelem matematiky" is the level of formality.


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## werrr

kelt said:


> This construction is used only in the written form and, as far as I remember, nobody would say it.


I dare to disagree with this. The construction is definitely more frequent in the formal style, but it is common in the colloquial Czech as well.

Besides of the construction "Nechť ... pak" (= Let ... then), it's possibly the most common construction in Mathematics.



> Nominative would be equally fine, instrumental could be slightly more formal/older.


No in Mathematics (and administrative and legal texts), there is rule to use the instrumental to make clear what is the subject.



			
				winpoj said:
			
		

> I wonder, Jana, what you base this explanation on. It may be due to a gap in my knowledge...


I just want to confirm the Jana's explanation. We recently broached this topic in this thread concerning the difference between "je pravda" and "je pravdou". The nominative construction is used for "absolute truth", while "instrumental" is used whenever the truth is relativized.

Je pravda, že se Rakušanům první zápas s novým trenérem podařil.
Je pravdou, že se Rakušanům s novým trenérem daří. (zatím )



> ...but I've always thought that the only difference between "je učitel matematiky" and "je učitelem matematiky" is the level of formality.


Učitel na odpočinku, ač již není učitelem, je stále učitel.


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## kelt

werrr said:


> I dare to disagree with this. The construction is definitely more frequent in the formal style, but it is common in the colloquial Czech as well.
> 
> Besides of the construction "Nechť ... pak" (= Let ... then), it's possibly the most common construction in Mathematics.



Well, I still think nobody would say it. Ok, maybe lawyers and politicians:
_Pak-li, že je tomu tak, vyšetříme to._

This is not colloquial. Nobody says:
_Pak-li, že jdeš nakoupit, vem pár piv.
Potkáš-li Katku, přiveď ji s sebou._


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## Jana337

kelt said:


> Well, I still think nobody would say it. Ok, maybe lawyers and politicians:
> _Pak-li, že je tomu tak, vyšetříme to._
> 
> This is not colloquial. Nobody says:
> _Pak-li, že jdeš nakoupit, vem pár piv.
> Potkáš-li Katku, přiveď ji s sebou._


Pakliže is one word. 



> I wonder, Jana, what you base this explanation on. It may be due to a gap in my knowledge, but I've always thought that the only difference between "je učitel matematiky" and "je učitelem matematiky" is the level of formality.


 I remember I was taught at school that the nomitative is more for expressing the identity of A and B or permanent features. I think that the teacher mentioned that you would say "_Země je středem vesmíru_" in the 10th century but "_V 10. století si lidé mysleli, že Země je středem vesmíru_".

Příruční mluvnice češtiny, rok vydání 2003, NLN: 
_Pokud jde o sémantické diference, platí obecně pravidlo, že Nom se užívá tehdy, jde-li o v širokém smyslu ztotožnění toho, co je označeno podmětovým výrazem, s tím, co označuje substantivum v přísudku.
(...)
Volba Nom nebo Instr (Otec *je učitel *x Otec *je učitelem*) záleží na záměru mluvčího vyjádřit buď zařazní někoho nebo něčeho do třídy, tj. relativně stálou vlastnost (Jeho otec *je učitel*), nebo naopak funkci někoho nebo něčeho, tj. vlastnost přechodnou (Jeho otec j*e učitelem*).

_Of course, the book also mentions that - where there is choice - the instrumental is more common in formal speech.


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## kelt

Jana337 said:


> Pakliže is one word.



Hehe  My bad.


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## winpoj

OK, it was indeed a gap.


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## jazyk

> I wonder, Jana, what you base this explanation on. It may be due to a gap in my knowledge, but I've always thought that the only difference between "je učitel matematiky" and "je učitelem matematiky" is the level of formality.


Narazil jsem na něco, co Janin dojem potvrzuje: První pád po sponovém slovese být tedy vyjadřuje trvalost, stálost, neměnnost a obecnější platnost (např. jeho_ dědeček byl Němec_), zatímco sedmý pád naznačuje spíše aktuálnost, dočasnost, přechodnost (např. _dědeček byl novinářem_).


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