Hi everyone. I am a new member. Please check grammar for me!

1.
A: What time did the mail arrive this morning?
B: It came while I was having breakfast.

2.
A: Was Tracey at work today?
B: She wasn't going  to work. She was sick. <--- This sentence would be a reply from someone who did not know definitely about Tracey. The person was told something in advance

C: She wasn't at work. She was sick.  <--------------- This sentence  was from someone who was present at Tracey's work and  definitely knew she was not there.

The word "sick" - this implies that the person was vomiting.

The word "ill"  - this covers a range of things that Tracey might have had - vomiting, diahorrea, headache, fever, nausea, cramps   etc. It is a more general term

3.
A: How fast were you driving when the police stopped you?
B: I'm not sure, but I wasn't driving very fast.
4.
A: How did you break the window?
B: We were playing  baseball. I hit the ball and it broke  the window.

5. Is it correct?
What games did you used to play when you were a child?  - <em>OK</em>

What games did you play when you were a child ? ----<em>- more common.</em>

6. He used to work in factory = he worked in a factory.
Please help me! thank you so much :)