This shirt isn't big enough.

这件衬衣不够大。

《牛津词典》

This house isn't big enough for us.

这房子对我们来说不够大。

《牛津词典》

Well, it really isn't big enough for corn.

它真的不够大，不能种玉米。

youdao

The gap isn't big enough.

这个间隙不够大。

耶鲁公开课 - 文学理论导论课程节选

The world isn't big enough for China to rise up the value-added chain without generating domestic consumer spending.

WSJ: Diana Choyleva: China Is Too Large for Its Own Good

We're making heavy investments and unfortunately if the site isn't big enough you can't just simply enlarge the school.

BBC: School child

If the screen isn't big enough by itself, there's a very distinct possibility we'll finally see LTE in the iPhone.

ENGADGET: iPhone 5: the rumor roundup Mobile