at a loss

He was at a loss what to do next.

Il ne savait plus quoi faire.

I was at a loss as to what to say.

Je ne savais plus quoi dire.

Tom was at a loss how to express himself.

Tom ne savait pas comment s’exprimer.

I'm at a loss about what to do with the mess.

Je ne sais plus quoi faire de ce bazar.

He was at a loss what to do.

Il ne savait plus quoi faire.

No, I'm afraid not but you have me at a loss.

Non, j’en ai bien peur, mais vous me laissez perplexe.

— Die Hard (1988)

She was at a loss as to what to do.

Elle ne savait pas quoi faire.

I'm at a loss.

Je ne sais plus quoi faire.

— Seven Samurai (1954)

I'm selling my car at a loss.

Je vends ma voiture à perte.