First Aid

We're having swimming lessons at school from next year, so recently we learned about first aid. We had a lecture about heart massaging and how to use an AED. I am not very strong so it was hard for me to press the chest down by one third. The most surprising thing was that a heart massage is more effective than an AED. I hope the students enjoy their swimming lesson and stay safe.

I miss Japan. Good English.

Phil.

first aid

We have a swimming lessons in school starting next year.
So we learned about first aid.
We had a lecture about a heart massages and how to use AED.
I am not powerful / strong, so it was hard to press the chest to one third depth.
The most surprising thing was a heart massage is more effective than AED.
I hope students enjoy their swimming lessons safely.

Notes: I hope I understood correctly what you were trying to say. The most confusing line for me was the first. Overall, though, very good.