notice不是感官动词吗?为什么这句话重用的是tobe而不是be,难道是this的定语?补充感官动词只接do（原形）Wenoticethistobetrueveryoftenwithdogsandcats.

Question

notice 不是感官动词吗?为什么这句话重用的是to be 而不是be,难道是this的定语?
补充感官动词只接do（原形）We notice this to be true very often with dogs and cats.

Answer 1

notice和know都属于感官动词,但这两个动词比较特殊,如果后面跟的是一般动词,就用不带to的动词不定式的形式,如果后面跟着be动词,就要用带to的动词不定式形式to be,比如：
I noticed him come in.
I noticed this to be a fact.
Have you known me tell a lie?
Never did I know her tell a lie.
I know this to be a fact.
希望我能帮助你解疑释惑.