彼らは大部分が若者だった。

彼らは大部分が若者だった。

They were for the most part young people.

彼(かれ)らは大(だい)部分(ぶぶん)が若者(わかもの)だった。

Karera wa dai bubun ga wakamono datta.

彼ら (かれら)

they (usually male); them

は (は)

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

大 (おお)

big; large

部分 (ぶぶん)

portion; section; part

が (が)

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

若者 (わかもの)

young man; young woman; young people; youth; youngsters

だ (だ)

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

Readings: ヒ、かれ、かの、か.の

Meanings: he, that, the

Readings: ダイ、タイ、おお-、おお.きい、 -おお.いに

Meanings: large, big

Readings: ブ、 -べ

Meanings: section, bureau, dept, class, copy, part, portion, counter for copies of a newspaper or magazine

Readings: ブン、フン、ブ、わ.ける、わ.け、わ.かれる、わ.かる、わ.かつ

Meanings: part, minute of time, segment, share, degree, one's lot, duty, understand, know, rate, 1%, chances, shaku/100

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

Readings: シャ、もの

Meanings: someone, person