won't do · be out of the question · be no good · not work · not be capable

Those shoes won't do for climbing.

If it's okay for him to buy a knife, then why on earth can't I?

I can't take it anymore! I haven't slept for three days!

That's a bad day for me.

Honey, come to bed. "No, not yet. I still have to translate some sentences on Tatoeba."