In the field of linguistics there are several elements that are studied in order to understand the semantics, syntax, and morphology of a language.
Contrastive analysis is a practice used in our field to, as the name itself says, contrast one language from another. We do this in order to categorize and differentiate their structure, and sometimes when we differentiate we are also able to compare and look for similarities that arise as a result of our investigation.
Why do this? If you think about it, language is an ever-changing communication tool. Contrastive analysis helps us understand what changes the language has undergone, and whether these changes are similar to any other language. It is the best way to tell the story of the language from the basic foundations of the human proto-language and all the way until modern time.
The most interesting aspect of contrastive analysis is that it gives us the chance to make connections. Change is often the result of a shift in some historical or social element such as demographic influx, the advent of war, political unrest, and economic changes, among others. When we make a social connection within a linguistic perspective, we are literally analyzing history. The connections between social changes and language changes are extremely interesting, and can only be discovered with the use of a contrastive analysis. Therefore, contrastive analysis is one of the most interesting and useful practices in the field of linguistics.