Can't manage it (too much, too hard): verb + không nổi / không xuể

After a verb, không nổi says you can't manage something because it's too much for you: too heavy, too far, too hard, too expensive. Nặng quá, em xách không nổi. It's too heavy, I can't lift it. Nổi here means having the strength for it.

Không usually goes after the verb, as in xách không nổi; before it, không xách nổi, is also fine. To ask whether someone can cope, put nổi không at the end: Còn xa lắm, anh đi nổi không? It's still a long way, can you manage? Answer Nổi or Không nổi.

It works for money too: Mắc quá, em mua không nổi. It's too expensive, I can't afford it (in Hà Nội, Đắt quá). And chịu không nổi means "can't stand it": Nóng quá, chịu không nổi!

When there's too much to keep up with, you'll also meet không xuể: Đơn hàng nhiều quá, làm không xuể. It's standard in writing everywhere, and common in set phrases like đếm không xuể, too many to count. In everyday Saigon speech, không nổi usually covers both.

Compare được: Em ăn không được means you can't eat it, perhaps because it's too spicy; Em ăn không nổi means you've had all you can manage. Kịp is about time: làm không kịp means you can't finish in time.