What it means
てならない expresses an emotion, concern, desire, or physical sensation that is so strong that the speaker cannot suppress or control it. It commonly describes an involuntary feeling, especially in formal or carefully expressed writing and speech. It attaches to a verb in the て-form, an i-adjective in its く-form, or a na-adjective with で. The polite counterpart changes the ending to なりません.
Usage note
てならない usually describes the speaker's strong inner feeling, or a feeling attributed to another person when the context makes that clear. It is not simply a stronger equivalent of とても or どうしても; those expressions have different meanings and uses. Do not interpret ならない here as its ordinary standalone meaning of "must not" or "cannot be allowed."
How to use it
試験の結果が心配でなりません。
I cannot stop worrying about the exam result.
故郷が恋しくてなりません。
I miss my hometown intensely.
その知らせが気になってなりません。
I cannot stop thinking about that news.
試験の結果が心配でならない。
I cannot stop worrying about the exam result.
故郷が恋しくてならない。
I miss my hometown intensely.
その知らせが気になってならない。
I cannot stop thinking about that news.
Example sentences
卒業を目前にして、研究室で過ごした日々が懐かしくてならない。
With graduation just ahead, I cannot help but feel nostalgic about the days I spent in the laboratory.
災害で離れて暮らす家族の安否が心配でならない。
I cannot stop worrying about the safety of my family members who live apart because of the disaster.
長年使ってきた腕時計を