Linguistics Stack Exchange is a question and answer site for professional linguists and others with an interest in linguistic research and theory. It only takes a minute to sign up.
Sign up to join this community
I don't know much at all about the specifics of Arabic grammar, so this question might not make sense, but as I understand it, most Arabic words consist of a three-consonant root with vowels inserted to alter the meaning / part of speech.
My question is, do loanwords take part in this process, or are they unaffected by it?
Loan words in Arabic are generally borrowed in something approaching their original form, but they are often perceived as being built around a three or four-letter root, from which purely Arabic derivatives can be formed. E.g. Greek philosophos was borrowed into classical Arabic as faylasūf, then reanalysed as f-l-s-f, with the regular Arabic plural falāsifa, and the de-nominal verb tafalsafa “to philosophise”.
Not all words can - according to Arab grammarians - be etymologized, which means in practice: be reduced to a verbal root from which they derive.
Therefore, for example, while you will find most words in Arabic dictionaries subsumed under their respective root (e.g. "muslim" not under the letter "mim", but under the root s-l-m), other words are not subordinated under a root, because they cannot. Now, as fdb pointed out, some loans, once they are perceived as Arabic, can be squeezed into that pattern. Others are "left alone", perhaps not being important enough to generate a need for related words of the same general concept. Still they may undergo the same treatment as native Arabic words.
An example are the so called "retrograde singulars". From Greek yakinthos "jacinth, hyacinth" Arabic "یواقیت", "yawāqīt" was borrowed, therefrom a new singular "یاقوت", "yāqūt", was formed.
