语法: 以后

这些句子是否正确？谢谢

1. 来美国，我认识了我的朋友
2. 你一个年以后开始上班吗？
3. 下午二点以后我在家
4. 下午五点以后，我们吃饭
5. 上午十一以后，你想去吗?

1. When I came to the United States, I met my friends
2. Will you start working in a year?
3. I will be at home after 2 p.m.
4. After five o'clock in the afternoon, we will have dinner
5. Do you want to go after 11am?