经过几个月的训练，他已经习惯了早起。

After months of training, he has become habituated to waking up early.

habituated 是动词 habituate 的过去分词形式，habituate 由词根 habit（习惯）和后缀 -uate（使成为）组成，意思是"使习惯于"。habituated 表示"已经习惯的、适应了的"。