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

§ 12. Synonymy

In the course of its long history the English language has adopted a great many words from foreign languages all over the world. One of the consequences of extensive borrowing was the appearance of numerous derivational affixes in the English language. Under certain circumstances some of them came to overlap semantically to a certain extent both with one another and with the native affixes. For instance, the suffix -er of native origin denoting the agent is synonymous to the suffix -ist of Greek origin which came into the English language through Latin in the 16th century. Both suffixes occur in nouns denoting the agent, e.g. teacher, driller; journalist, botanist, economist, etc. Being synonymous these suffixes naturally differ from each other in some respects. Unlike the suffix -er, the suffix -ist is:

1. 
   mostly combined with noun-bases, e.g. violinist, receptionist, etc.;
   
2. 
   as a rule, added to bases of non-Germanic origin and very seldom to bases of Germanic origin, e.g. walkist, rightist;
   
3. 
   used to form nouns denoting those who adhere to a doctrine or system, a political party, an ideology or the like, e.g. communist, Leninist, Marxist, chartist, Darwinist, etc. Words in -ist denoting 'the upholder of a principle' are usually matched by an abstract noun in -ism denoting 'the respective theory' (e.g. Communism, Socialism, etc.).
   

Sometimes synonymous suffixes differ in emotive charge. For instance, the suffix -eer also denoting the agent is characterised, in particular, by its derogative force, e.g. sonneteer — стихоплет, profiteer — спекулянт, etc.
There is also a considerable number of synonymous prefixes in the English language. Recent research has revealed certain rules concerning correlation between words with synonymous prefixes of native and
foreign origin. It appears, for instance, that in prefixal-suffixal derivatives the general tendency is to use a prefix of Romanic origin if the suffix is also of Romanic origin and a native prefix in the case of a native suffix, cf. unrecognised — irrecognisable; unlimited — illimitable; unformed — informal; undecided — indecisive, etc. Though adequately reflecting the general tendency observed in similar cases this rule has many exceptions. The basic exception is the suffix -able which may often occur together with the native prefix un-, e.g. unbearable, unfavourable, unreasonable, etc. In fact, the pattern un- +(v + -able) -> A is wide-spread and productive in Modern English.