The matter of synonyms in langauges is an interesting part of the subject “Lexicology”. However, this topic can is and has been investigated from different aspects: grammatical, syntactical, stylistic ones. Synonyms, especially, grammatical synonyms can be confused with “variation” or “variants”. The article touches on this matter, alongside with the compasriosn of grammatical synonyms in tense forms of English and Azerbaijani.comparative. So, past, present and future tense forms and the grammatical forms creating these tense forms of both languages are compared here and some nice examples taken from literature are given to illustrate the investigated matter.