litigate vs sue

litigate and sue both are verbs.

Word	Noun	Adjective	Verb	Adverb
litigate	No	No	Yes	No
sue	No	No	Yes	No

As verbs, litigate and sue are synonyms defined as:

litigate and sue: institute legal proceedings against; file a suit against

Other synonyms of litigate include action, process.

litigate (verb)	sue (verb)
institute legal proceedings against; file a suit against	institute legal proceedings against; file a suit against
engage in legal proceedings