"बच्चे नाश्ते के बाद सोते हैं।"
अनुवाद:The children sleep after breakfast.
We do not use the word "the" for certain situations when we are talking about meals. We say "after breakfast", "before lunch", "during dinner", "for breakfast" etc. You can see more information about this here and here.
Saying "the breakfast" means you are talking about one specific breakfast - which doesn't make sense in this context because no specific breakfast is being referenced. We could use "the" if a specific breakfast was being referenced:
- Everyday I eat the same breakfast as you.
- I like the breakfast that the Hotel gives us.
- The breakfast I had yesterday was not nice.
Notice how in these three sentences above a specific breakfast is being talked about.