他及时赶回来的可能性不大。

There's a slight chance that he'll be back in time.

《牛津词典》

这事可能性不大，但也不是不可能。

It is unlikely but not impossible.

youdao

审判赢得国际认可的可能性不大。

The chances that the trials will win international recognition appear slim.

youdao

If the stock went up yesterday, it's more likely to go up today, than if it didn't go up yesterday.

如果股票昨天涨了，今天涨的可能性也就更大，如果昨天没涨今天也不大可能会涨。

麻省理工公开课 - 计算机科学及编程导论课程节选

Hopefully within two years, probably not next year, but within two years, there will be positive psychology class offered, but I certainly cannot guarantee it.

但愿两年内，明年可能性不大，但是两年内，学校会再次开设积极心理学课程，但我无法保证。

哈佛公开课 - 幸福课课程节选