我是不是挑了個不恰當的時間跟你談話？
Have I picked a bad time to talk to you?
通常情況下，我是不會看到這封信的。
Normally, the letter would not have come to my notice.
我是外國人這事實對我十分不利。
The fact that I was a foreigner was a big disadvantage.
我是愛莫能助啊。
It is not within my power to help you.
我是老主顧，他們都認識我。
They know me ─ I'm a regular customer.
他談話中使用的行話對我是一團迷霧。
The jargon in his talk was opaque to me.