I'm sorry I couldn't come to the class today.
The truth is I overslept and missed the train.
じつは、あさねぼうして、でんしゃにのりおくれたんです。
That's already the third time.
Why don't you buy an alarm clock?
As for the homework - could you please wait until tomorrow?
I can't find the file I put my homework in. [lit. There's no file...]
I hope you'll find it [lit. I hope it will be found.]
It's blue and about this big.
I think I left it when I got off the train...
でんしゃをおりるとき、わすれたとおもうんですが。。。
I'll [try to] make a call and ask.
でんわしてきいてみます。ーてみる (TO TRY) ≠ みたいです (LOOKS LIKE)
A station attendant found it for me.
The station attendant helped me [I recieved help from him].