Hi, how do you say the Greek word acquisition or acquire language? I can not find it. I don’t want the word learn and learning. I send examples of sentences to make it clear what exactly I mean. Thank you.
Language acquisition is the process by which humans acquire the capacity to perceive and comprehend language.
How to acquire any language not learn it!
You’re operating with a false dichotomy. The Greek word for acquisition is κτῆσις, but that doesn’t apply to languages. To “acquire” a language is to learn it, whether or not through study. The word is μανθάνειν.
(As for acquiring a capacity for language, Aristotle would say it’s by imitation.)
The best way to understand this is to acquire knowledge of Greek, i.e. to learn Greek. There are people here who can help you in that endeavor.
I make no claim to any ability in Greek composition, but this reminded me of Sidgwick’s advice on translating the sense of an English sentence into Greek, which may be helpful for others passing by:
SENSE
We have seen that one great difference between the idiom of Greek and English lies in the fact that the Greeks preferred often to express in the concrete what we express in the abstract. This is a very important point, and the learner will constantly have to be reminded of it.
There are many other ways, however, besides this, in which the greater complexity and artificiality of much English writing (especially in more modern times) is unsuited to Greek idiom, and requires to be recast in the translating.
It is a good general rule, therefore, whenever the learner has to translate into Greek any English phrase at all artificial or idiomatic – indeed in all composition except the simplest narrative – to accustom himself always to think of exactly what the fact is that is being related, and to shake himself quite free from the form in which (in the English) that fact is conveyed. If he clearly grasps the notion that everything is best put into Greek in the simplest and most direct way, he will at once make a great improvement in his style, and be saved from falling into innumerable unnaturalnesses of expression, which may be quite logically and grammatically correct, without being idiomatic : that is, without being good Greek.
I can only assume that he’s being droll with “innumerable unnaturalnesses of expression”!
Maybe ἀνάληψις. Bailly defines it as: acquisition (de connaissances, de vertu, etc.)
Can you clearly say what the difference is in English (or French?) between “to learn” and “to acquire” when it comes to languages?
The first Google result for a definition of ‘acquire’ has:
In academic writing, there’s a difference between “language learning”, which focuses more on pedagogy (παιδαγωγία 
) and active learning methods, and “language acquisition” which tends to deal with learning in childhood and the psychological/neurobiological side of learning a language. But this strikes me as a modern distinction and I would trust mwh if he thinks Greek wouldn’t separate these meanings. From what I can see, even acquiro in Latin can’t bear this sense of acquiring a language (but there are some excellent Latinists on Textkit who could tell you either way).
In English, we can also say “to pick up a language” but that doesn’t mean we should translate it as ἀναιρέω (or λέγω! LSJ A.I.1).
Thank you for all your answers 
I already found it.
Jean Efpraxiadis wrote me this on Facebook:
You could use the noun κατάκτησις which means acquisition and the verb κατακτάομαι (to gain completely for oneself), so γλώσσης κατάκτησις (language acquisition) could perhaps be distinguished from γλώσσης μάθησις (language learning). Of course Chomskian theories and terminologies didn’t exist in ancient times, but hey, i am trying to help. While κατάκτησις has not been used in connection with language as far as I can tell, it does appear to have been used in connection with acquiring rhetorical prouesse, so I think it’s a good try. Besides, in modern Greek, language acquisition is called γλωσσική κατάκτηση, so there you go.
I’m glad you’ve found a coinage you’re happy with. I suppose it depends on what you’re trying to achieve. My instinct is that if ancient Greeks were going to make the Chomskyan distinction between language acquisition in childhood and language learning in later life it wouldn’t be rendered as a noun phrase (NP 
) but using a verb/articular infinitive, so “learn to talk” (in childhood - μαθεῖν λέγειν) or similar for acquisition and “learn a tongue” (as an adult - μαθεῖν/ἐκμαθεῖν γλῶτταν) for language learning, but I’m happy to be proven wrong on that.
If we’re in our time machine asking the Greeks what they think about Chomsky’s linguistic philosophy, I’d love to ask them what they make of his politics.