he suddenly realized that what he had done...

[嘟嘟嘟嘟]

"He suddenly realized that what he had done was really foolish."

Is it right to leave"that" there in the sentence? Shouldn't it be omitted? Thanks for help!

 

[MikeNewYork]

It is correct either way. I prefer it without "that"..

 

[Rover_KE]

I agree it's correct either way. I prefer it with 'that'.

 

[emsr2d2]

I prefer it with "that" solely because it tells the listener that the sentence isn't just going to be "He suddenly realised what he had done". That is a perfectly grammatical sentence but, by adding "that", we know that something more is to come after "what he had done".