Hi David,
What a great idea! 
I really like Ms. Steen a lot. 
She helped me to improve my English so much. 
I'm sad to see her go, and this party is the best way to say "Thank you and goodbye. 
"I can help to buy some of the food and drinks. 
I can also help to bring Ms.Steen to the party. 
I already have a great idea about how to do that.
He Wei

-------------- 

Hi David,
Thanks so much for planning this. 
I'd love to come to the party, but I'm not available.
My family is taking a trip to Wuhan at the end of this month to visit my aunt and uncle. 
However, I'd still be glad to help out with any of the party preparations, 
like planning the games. 
Let me know if you need my help.
Jake

-------------------

Dear classmates,
As I'm sure you know by now, our favorite teacher, Ms.Steen, is leaving soon to go back to the US. 

We're very sad that she's leaving because she is a fun teacher. 
To show how much we're going to miss her, 
let's have a surprise party for her next Friday the 28th!
Can you come to the party? 
If so, can you help with any of these things? 
Please tell me by this Friday.

1) Buy food and drinks.

2) Think of games to play.

3) Prepare things we need for the games (glue, paper, pens,...).

4) Bring Ms.Steen to the party without telling her so that she can be surprised.

I look forward to hearing from you all.

David