Some verbs are not usually used in the continuous form, even when we are talking about temporary situations or states. These are called stative verbs.
So, we say I’m sorry, I don’t understand rather than I’m not understanding.
1. Stative verbs are often verbs connected with thinking and opinions.
She doesn’t know what to do NOT She isn’t knowing what to do
Do you agree with me?
I don’t recognize it, do you?
Other verbs in this groupinclude：
believe, doubt, guess, imagine, mean, remember, think
2. Other stative verbs are connected with feelings and emotions
I like this song. Who sings it? NOT I’m liking this song
What do you want to do now?
I hate my new boss!
Other stative verbs in this group include:
dislike, love, prefer. want, wish
NB – although ‘enjoy’ is a verb of emotion, it is used in the continuous tense
I’m enjoying the party.
3. ‘see’, ‘hear’, ‘taste’, ‘smell’, ‘feel’ are verbs that describe senses.
3. ‘see’, ‘hear’, ‘taste’, ‘smell’, ‘feel’等描述感官的动词
These verbs aren’t usually used in continuous forms. They are often used with ‘can’.
It smells of smoke in here. NOT It’s smelling of smoke in here
I can’t see anything. It’s too dark.
4. Stative verbs describe things that are not actions.
Look carefully at these 2 sentences.
He smells of fish.
He’s smelling the fish.
The second sentence is an action – not a state. The man wants to know if the fish is OK to eat.
I think we should go to Croatia for our holiday this year.
Sorry, what did you say? I was thinking about my holiday.
The first sentence is an opinion but the second sentence is an action.