when they are angry

[navi tasan]

1) You know Tom when he is angry.
2) You know how Tom is when he is angry.

Can #1 be used instead of #2?


3) You know children when they are angry.
4) You know how children are when they are angry.

Can #3 be used instead of #4?

 

[5jj]

If you wish.

 

[Tarheel]

In my humble opinion, more likely is:

You know how Tom is when he's angry.

 

[emsr2d2]

More natural in BrE would be "You know what Tom's like when he's angry" and "You know what kids are like when they're angry".