1.Did this tree fall of itself yesterday?
2.Did this tree fall by itself yesterday?
1.This is himself's fault.
2.This is his own fault.
1. That student bought herself an English dictionary yesterday.
2. That student bought an English dictionary by herself yesterday.
He let himself down slowly by means of a rope.
- TOMING88Lv 78 年 前最佳解答
Herself is a pronoun being the reflexive form of she used when the girl who performs an action is also affected by it:
Hence (-)bought herself an English Dictionary be correct.
Hence fall of itself means also be affected by itself be correct.
Hence this is his own fault himself be correct.
"let himself down" means climb down,which is an adverb,
"slowly" is another adverb,which is adverb of manner.