English is one of the most strongly analytic languages (Chinese being even more extreme) - it determines word relationships and function with word order and helper words.
Whereas Standard Arabic, Ancient Latin, and Finnish are very synthetic, changing words to indicate their function and relationship to other words in the sentence. If your language has the concept of "declensions", it's probably on the synthetic end of the spectrum.
Interestingly, after observing an increase in analyticity over time in European languages, some linguists have hypothesized that analytic languages are easier for foreign speakers to learn as adults, and that this causes languages with lots of geographic spread and inter-language contact to become more and more analytic. With creole languages being of course the most striking example.