Phrases Asking for Favors or Assistance

Let me know if you can...

Meaning

Requests help and asks for confirmation of availability.

Translation language

John: I need some help moving these boxes. <b>Let me know if you can</b> lend a hand this afternoon.
Alice: I'll check my schedule. I can probably help. How many boxes are there?
John: About ten, fairly heavy ones. <b>Let me know if you can</b> manage that.
Alice: Okay, I'll confirm by lunchtime.