英语提问：介词后面不是只能接名词、动名词吗,下列句子怎么接的全是形容词?

was told about it in private.
The motor operates well as usual.
I noticed her eyes in particular, because they were very big.
这三个例句里
in private
as usual
in particular
都是副词短语, 不是形容词.
in private = privately
as usual = in the usual manner
in particular = particularly
这都是习语.
希望帮到了你.