天啊:

1. Lord

2. My, how he's grown!

Examples:

1. 天啊！这是我在这个星期第三次丢失了办公室的钥匙。

Oh dear! It's the third time I've lost my office key this week.

2. 天啊！不要在我宿醉后还要叫我跑步。

Oh, my god! Do not make me run with this hangover.

3. 哦！天啊！我英文没有考及格！

Oh, dear! I failed in the English examination!