哪些词后只接原级

1.在这些表示绝对概念的副词very，so ，too， enough，quite 之后时，用形容词原级

例如:The boy is too young.

The classroom is very large.

2.在肯定句：as ...as ...中用原级

例如:English is as interesting as Chinese.

This book is as thick as that one .

2）在否定句否定句：as/ so...as...加形容词原级 

Tom is not so tall as Tim.

This village is not as big as that one.

3）表示倍数时+形容词原级

Our school is three times as big as theirs.

The table is twice as tall as the chair.

4) 表示…..是…..的一半时， 加形容词原级

Her room is half as big as yours.

The red pencil is half as long as the blue pencil.