疲れきる, 疲れ切る, つかれきる
Conjugated: 疲れ切っていた
Godan verb
to be exhausted, to be tired out
あなたは一日中働いた後で疲れきっているにちがいない。
が
Particle
1. indicates sentence subject (occasionally object)
2. indicates possessive (esp. in literary expressions)
Conjunction
3. but, however, still, and
after the volitional form of a verb
4. regardless of, whether (or not)