Is "что" mandatory?

Question

If I wanted to say "I know he loves Russia," could I say `Я знаю, он любит Россию` or would it have to be `Я знаю, что он любит Россию`?I know that in English it is more proper to use 'that,' however I'm not sure how this works in Russian. Is it different for colloquial speech vs. proper grammar?

Answer 1

No, что is not mandatory. Both of your sentences are correct.

Answer 2

You can say either “Я знаю, что он любит Россию» or “Я знаю, он любит Россию.” Both sentences are correct, but the variant without “что” is used only in colloquial speech. For proper written Russian the use of “что” would be necessary here.