I'm afraid I can't remember the way.

恐怕我不记得路了。

《柯林斯英汉双解大词典》

I'm afraid I can't afford it.

恐怕我买不起。

youdao

I'm afraid I can't speak in public.

恐怕我不能当众讲话。

youdao

I'm afraid I can't quite accept that.

恐怕我无法接受这种观点。

普林斯顿公开课 - 人性课程节选

I'm afraid I can't let some extreme and unfounded comments go unchallenged.

BBC: Is Marion Jones right to drop coach?

"I'm afraid I can't say more, " he teases.

FORBES: Three men and a Web idea

I'm afraid I can't do that.

NPR: Space Race Permeated Pop Culture