thus far vs til now

thus far and til now both are adverbs.

Word	Noun	Adjective	Verb	Adverb
thus far	No	No	No	Yes
til now	No	No	No	Yes

As adverbs, thus far and til now are synonyms defined as:

thus far and til now: used in negative statement to describe a situation that has existed up to this point or up to the present time

Other synonyms of thus far include as yet, heretofore, hitherto, so far, until now, up to now, yet.

thus far (adverb)	til now (adverb)
used in negative statement to describe a situation that has existed up to this point or up to the present time	used in negative statement to describe a situation that has existed up to this point or up to the present time