+0
http://www.google.com/search?hl=en&rlz=1C1GGLS_jaJP291JP303&q=site:*.co.uk+"humming+along&start=1...

eg.

I just put it on and everyone in the car was quiet or happily singing/humming along

What's the difference between 'humming' and 'humming along'?

Thanks.
+0
Hi LiJ

When you hum along or sing along there must be background music, and you hum or sing with music you are listening to.

You can hum or sing with or without background music.
Comments  
Understand!!!
Thanks, Amy.