エレンはたいそう疲れていたので早く寝た。

Ellen was so tired that she went to bed early.

エレンはたいそう疲(つか)れていたので早(はや)く寝(ね)た。

Eren wa taisō tsukareteita node hayaku neta.

は (は)

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

大層 (たいそう)

very much; exaggerated; very fine

疲れる (つかれる)

to get tired; to tire; to be worn out (e.g. of well used objects); to starve

ので (ので、んで)

that being the case; because of ...; the reason is ....; given that...

早い (はやい)

fast; quick; hasty; brisk; early (in the day, etc.); premature; (too) soon; not yet; (too) early; easy; simple; quick

寝る (ねる)

to lie down; to go to bed; to lie in bed; to sleep (lying down); to sleep (with someone, i.e. have intercourse); to lie idle

Readings: ヒ、つか.れる、 -づか.れ、つか.らす

Meanings: exhausted, tire, weary

Readings: ソウ、サッ、はや.い、はや、はや-、はや.まる、はや.める、さ-

Meanings: early, fast

Readings: シン、ね.る、ね.かす、い.ぬ、みたまや、や.める

Meanings: lie down, sleep, rest, bed, remain unsold