R. S. Ginzburg, S. S. Khidekel, G. Y. Knyazeva, A. A. Sankin a course in modern english

§ 30. Relations between the ICs of Compounds

From the point of view of degree of semantic independence there are two types of relationship between the ICs of compound words that are generally recognised in linguistic literature: the relations of coordination and subordination, and accordingly compound words fall into two classes: coordinative compounds (often termed copulative or additive) and subordinative (often termed determinative).

In coordinative compounds the two ICs are semantically equally important as in fighter-bomber oak-tree, girl-friend, Anglo-American. The constituent bases belong to the same class and most often to the same semantic group. Coordinative compounds make up a comparatively small group of words. Coordinative compounds fall into three groups:

1. 
   Reduplicative compounds which are made up by the repetition of the same base as in goody-goody, fifty-fifty, hush-hush, pooh- pooh. They are all only partially motivated.
   
2. 
   Compounds formed by joining the phonically variated rhythmic twin forms which either alliterate with the same initial consonant but vary the vowels as in chit-chat, zig-zag, sing-song, or rhyme by varying the initial consonants as in clap-trap, a walkle-
   

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