きみが助けてくれていたなら、ぼくは成功していただろう。

If you had helped me, I should have succeeded.

きみが助(たす)けてくれていたなら、ぼくは成功(せいこう)していただろう。

Kimi ga tasuketekureteita nara, boku wa seikōshiteita darou.

君 (きみ)

you; buddy; pal; monarch; ruler; sovereign; (one's) master

が (が)

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

助ける (たすける)

to help; to save; to rescue; to give relief to; to spare (life); to reinforce; to promote; to abet

だ (だ)

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

僕 (ぼく)

I; me; you; manservant

は (は)

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

成功 (せいこう)

success; hit

Readings: ジョ、たす.ける、たす.かる、す.ける、すけ

Meanings: help, rescue, assist

Readings: セイ、ジョウ、な.る、な.す、 -な.す

Meanings: turn into, become, get, grow, elapse, reach

Readings: コウ、ク、いさお

Meanings: achievement, merits, success, honor, credit