有些感官动词是系动词,如：feel,sound,look（看起来）,taste,smell.多数感官动词不是系动词,如：watch,see,listen,hear,look(看),taste,smell,feel等等.
look,taste,smell,feel等词如果表示具体的动作,有动作的执行者或承受者,就不是系动词.如：
I look at a bag.
She smelt the soup.
He felt sick.
look,taste,smell,feel等词如果不表示具体的动作,只表示某物的性质或特点,就是系动词.如：
The bag looks nice.
The soup smells/tastes delicious.
The coat feels smooth.