doubtful

It is doubtful that the old car will make it across the country without breaking down.

(Chinese) 这辆旧车在不抛锚的情况下横穿全国是不太可能的。

The weather forecast said rain is doubtful, but we should bring umbrellas anyway.

(Chinese) 天气预报说下雨的可能性不大，但我们还是带上伞吧。