てならない (te naranai): Being unable to help feeling or thinking

Cannot help feeling; extremely

Te-form verb, i-adjective ending in くて, or na-adjective + で + ならない. Do not confuse this with prohibitive てはならない.

Describe a feeling, thought, or sensation that arises naturally and cannot be suppressed. Expressions such as ki ni naru, omoeru, and zannen da are common. This is entirely different from te wa naranai, which expresses prohibition.

友人のことが気になってなりません。

I cannot help being concerned about my friend.

祖母に会えなかったことが残念でなりません。

I deeply regret not being able to see my grandmother.

この説明には何か足りないように思えてなりません。

I cannot help feeling that something is missing from this explanation.

皆さんに助けていただいて、ありがたくてなりません。

I am deeply grateful for everyone's help.

あの約束を守れなかったことが、悔しくてなりません。

I feel deeply frustrated that I could not keep that promise.