जानता नहीं

doesn't know

→ जानना
phrase Uncommon #4,518
doesn't know जानता is the masculine singular form; the verb changes to agree with the subject. The more usual word order is नहीं जानता.
HI: वह जवाब जानता नहीं है।
EN: He doesn't know the answer.

बॉब जापान कब आया यह मैं जानता नहीं।

I don't know when Bob came to Japan.

"तू देख, इसलिए, क्योंकि तू जानता नहीं कब घर का मालिक आता है."

Look, because you don’t know when the owner of the house is coming.

— The Shawshank Redemption (1994)

टॉम वह जानता नहीं।

Tom doesn't know that.

देख अनुराग, तू जानता नहीं है इसको।

Look, Anurag, you don't know him.

— AK vs AK (2020)

जानता नहीं है किसकी बस है ये?

Don't you know whose bus this is?

— 12th Fail (2023)