彼はもうすっかりよくなった。

he; him; his; boyfriend

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

now; soon; shortly; before long; presently; already; yet; by now; (not) anymore; further; more; again; another; the other; interjection used to strengthen expression of an emotion (often exasperation)

all; completely; thoroughly

nicely; properly; well; skillfully; skilfully; frequently; often

to become; to get; to grow; to be; to reach; to attain; to result in; to prove to be; to consist of; to be composed of; to succeed; to be complete; to change into; to be exchanged for; to play a role; to be promoted; to do ...