The Latin language is today used in three secular contexts:

It also remains the official language of Vatican City and Roman Catholic doctrine:

Historically, it was the language of the Roman Empire and provided the origins of the following modern languages:
To facilitate easy translation, open politics itself may prefer a Latin form to an English form of a term or phrase, where the correspondence is exact, e.g. "i.e." ="id est" = "that is".

Accordingly it is quite important to know how to recognize a Latin word. This guide is very helpful.

See also Latin grammar, which must work, as there are still roads and aqueducts and stuff built using it... which is more than can be said for most stuff built by people using English gramar!