Determine

Use “settle” or “decide”. The technical meaning of “determine” in law is better replaced by “end” or “set an end to”.

Definitive

This word differs from “definite” by conveying the idea of finality. A definite offer is an offer precise in its terms. A definitive offer is an offer which the person making it declares to be the last word.

Credence, Credibility, Credulity

These words are sometimes confused. “Credence” means belief or trust, “credibility” the quality of being believable and “credulity” the quality of being ready to believe anything.

Convince

Do not use “convince” like “persuade”. You may convince people of a fact, or convince them that you are right, but you cannot correctly convince them to do something.

Consist

There is a difference between “consist of” and “consist in”. “Consist of” denotes the substance of which the subject is made; “consist in” defines the subject.