Translation of "Uncertain" in Dutch

Tom was uncertain.

Tom was twijfelachtig.

And into uncertain territory.

...op onbekend terrein.

The future is uncertain.

De toekomst is onzeker.

They admitted that they were uncertain.

Ze gaven toe dat ze onzeker waren.

Whether the medicine will work or not is uncertain.

De werking van het medicament is onzeker.

- I am not sure when he will come.
- I do not know for certain when he will come.
- I'm uncertain what time he is coming.
- I'm not sure when he'll come.

Ik weet niet zeker wanneer hij zal komen.