be at home

US /bi æt hoʊm/
UK /bi æt hoʊm/
"be at home" picture
1.

感到自在, 感到舒适

to be comfortable and relaxed in a particular place or situation

:
She always feels at home when she visits her grandmother's house.
她每次去奶奶家都感觉很自在
Even though it was a new city, he quickly began to feel at home.
尽管这是一个新城市,他很快就开始感到自在
2.

熟悉, 擅长

to be knowledgeable or proficient in a particular subject or area

:
He's an expert in ancient history; he's really at home with the subject.
他是古代史专家;他对这个主题非常熟悉
She's always been at home with numbers and complex calculations.
她一直对数字和复杂的计算很擅长