A logical problem
The mystery of the route
No child knows what language he or she is learning or when he or she has heard everything he or she needs to hear in order to have learnt the language. There are six or seven thousand odd languages in the world. But the learner has no guidance, no ‘privileged information’ as it is called by learnability theorists, on where his or her target language lies with respect to all the known variations. And children’s experience, what they happen to hear said, what sorts of conversations they get involved in vary randomly. This lack of certainty leads to what is known as ‘the logical problem of language acquisition’.
The variations are on two levels. On the one level there are the various categories, what are known as ‘parts of speech’, different sorts of speech sound like vowels and consonants, and so on. And on the other there are the different ways the categories are defined. This makes a strictly bottom-up search very difficult, if not impossible.
Every language has a way of referring to the various facets of experience, woman, child, mother, water, death, night, silence, known as ‘nouns’. But the way they appear varies widely, mainly in some sort of root form, as in English, or only with sort of additional structure as in Greek. In Greek this additional structure follows the root. In other languages the additional strucrture comes first, or both before and after the root, as in Russian. Most European languages add an element, mostly before the noun, as in English, with a very subtle role defining its relation to the discourse, traditionally known as ‘articles’. but nowadays as ;determiners’. But like classical Larin, Russian does not do this, achieving the same effect by the order of the words.
The most strongly contrasting category is represented in English by verbs, including the word, be, and its various forms. So in English we have “It’s hot”. But in some languages the same ideas are expressed by something more like “It hots” or “Hots”. Russian does this in the past tense.
At the extreme of exceptionality, consider the sentence “He takes sugar”. By what was once known as ‘Do support’ the marking of the present tense is moved to the left in questions and negatives, and realised in a form of the verb do in “Does he take sugar?” or “He doesn’t take sugar”. This way of marking questions and negatives is very unusual across languages. It is accordingly hard for children to learn.
There are similar problems with the sound structure. All languages allow syllables with one vowel and one consonant like key and toe, where the vowel is the nucleus. Some languages allow no other sorts of syllable. This is known as the ‘unmarked’ case, with cases of more complex structure representing progressively higher degrees of markedness. English, as well as allowing words like strength, with three sounds before the nucleus and three after it, also allows L as the nucleus of an unstressed syllabie in words like little.
In a more exteme way, at least one language, Tashlhiyt, spoken in North Africa, sometimes called ‘Berber’ to the great dislike of the speakers, allows any phoneme to constitute the nucleus of a syllable. It thus allows sentences consisting entirely of consonants, withut a single vowel.
There is thus a scale from the easily learnable to the not so easily learnable.