What it means
てもどうにもならない expresses that taking a certain action or being in a certain condition will not change the situation or produce a useful result. It often conveys resignation or the recognition that it is already too late to remedy something. It attaches to a verb te-form, to an i-adjective in its くて form, and to a noun or na-adjective followed by でも. The polite counterpart is てもどうにもなりません.
Usage note
This expression is stronger and more resigned than a general statement that something is useless. With verbs, the preceding action is often one that has already been considered or attempted, while with nouns and adjectives, the entire condition is presented as unable to change the outcome.
How to use it
相手が専門家でもどうにもなりません。
Even if the other party is a specialist, nothing can be done.
状況が不利でもどうにもなりません。
Even if the situation is unfavorable, nothing can be done.
条件が厳しくてもどうにもなりません。
Even if the conditions are strict, nothing can be done.
今さら後悔してもどうにもなりません。
Regretting at this point will not help.
相手が専門家でもどうにもならない。
Even if the other party is a specialist, nothing can be done.
状況が不利でもどうにもならない。
Even if the situation is unfavorable, nothing can be done.
条件が厳しくてもどうにもならない。
Even if the conditions are strict, nothing can be done.
今さら後悔してもどうにもならない。
Regretting at this point will not help.