Examples must not in Czech examples

How do I translate must not into Czech?

Simple sentences

Seeing that you're not surprised, I think you must have known.

Vida, že nejsi překvapen, domnívám se, že jsi musel vědět.

You must not take advantage of her innocence.

Nesmíš zneužít její nevinnosti.

You must be careful not to make him angry.

Musíš být opatrný, abys ho nerozzlobil.

Movie subtitles

And then to abandone Richard who she loved. How hard it must be not to die. Take it easy, ma'am.

A ona musela opustit svou životní lásku.