Consequently, words may be classified according to the difficulties students find in assimilation(إستيعاب). The analysis of the words within the foreign language allows us to distinguish the following groups of words: concrete, abstract, and structural.
Ch. Fries in his book "The structure of English" distinguished four types of words according to the function in the sentences and their combinability with other words: 1. Function words, ex. "do" signaling(مشيرا إلى) question 2. Substitute words, he, she, they etc.
3. Grammatically distributed words "some", "any"...
4. Content words
The number of words in the first three groups is rather small, say 200 in round numbers in English. The forth group, content words, constitutes the bulk of the language vocabulary.
Two further distinctions in vocabulary are required to complete our model. We need to distinguish between a common core vocabulary known to all the members of a language community and specialized vocabularies, known only to special groups. We are of course primarily interested in the common core vocabulary. The other distinction according to C. Friese is that between vocabulary for production and vocabulary for recognition. As a rule, our reception of vocabulary is much larger than our production of vocabulary.
Words denoting concrete things (book, street, sky), actions (walk, dance, read), and qualities (long, big, good) are easier to learn than words denoting abstract notions (world, home, believe, promise, honest). Structural words are the most difficult for Russian speaking...