go to bed vs turn in

go to bed and turn in both are verbs.

Word	Noun	Adjective	Verb	Adverb
go to bed	No	No	Yes	No
turn in	No	No	Yes	No

As verbs, go to bed and turn in are synonyms defined as:

Other synonyms of go to bed include bed, crawl in, go to sleep, hit the hay, hit the sack, kip down, retire, sack out.

go to bed (verb)	turn in (verb)
prepare for sleep	prepare for sleep
	carry out (performances)
	make an entrance by turning from a road
	to surrender someone or something to another