彼はまったく気が若い。

彼はまったく気が若い。

He is quite young in spirit.

彼(かれ)はまったく気(き)が若(わか)い。

Kare wa mattaku ki ga wakai.

彼 (かれ)

he; him; his; boyfriend

は (は)

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

全く (まったく)

really; truly; entirely; completely; wholly; perfectly; indeed; good grief (expression of exasperation)

気 (き)

spirit; mind; heart; nature; disposition; motivation; intention; mood; feelings; atmosphere; essence

が (が)

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

若い (わかい)

young; youthful; immature; green; low (number); small

Readings: ヒ、かれ、かの、か.の

Meanings: he, that, the

Readings: キ、ケ、いき

Meanings: spirit, mind, air, atmosphere, mood

Readings: ジャク、ニャク、ニャ、わか.い、わか-、も.しくわ、も.し、も.しくは、ごと.し

Meanings: young, if, perhaps, possibly, low number, immature