彼はうそつきだが、おまえもだ。

he; him; his; boyfriend

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

liar (sometimes said with not much seriousness); fibber

be; is; indicates past or completed action; indicates light imperative

indicates sentence subject (occasionally object); indicates possessive (esp. in literary expressions); but; however; still; and

you (formerly honorific, now sometimes derog. term referring to an equal or inferior); presence (of a god, nobleman, etc.)

too; also; in addition; as well; (not) either (in a negative sentence); both A and B; A as well as B; neither A nor B (in a negative sentence); even; as much as; as many as; as far as; as long as; no less than; no fewer than; even if; even though; although; in spite of; further; more; again; another; the other