Some verbs describe states and are not normally used in a continuous form.

State verbs:

1. describe emotions or mental states or processes

adore

appreciate (=value)

approve of

believe

care

consider (=hold an opinion)

detest

dislike

doubt

expect (=think)

fear

feel (=have an opinion)

find (=realise)

forget

gather (=understand)

hate

imagine

know

like

loathe

love

need

mind

perceive

prefer

realise

recall

recognise

recollect

regret

remember

require

see (=understand)

see through sb (=understand hidden motives)

suppose

suspect

think (=to have an opinion)

trust (=believe, have confidence in)

understand

value

want

wish

Exceptions: enjoy, long for

2. refer to the senses

feel

hear

notice

observe

see

smell

sound

taste

3. refer to communication

agree

apologise

deny

disagree

mean

promise

4. refer to exterior appearance

appear

look (=seem)

seem

5. refer to possession

belong to

have 

owe

own

possess

6. other state verbs include

be

concern

consist of

contain

cost

depend on

deserve

exist

fit

hold (=contain)

impress

include

involve

keep (=continue)

lack (BUT is lacking in)

matter

resemble

signify

suit

surprise

weigh

NOTE

We can use state verbs in the continuous when they describe an action

I'm thinking about/considering taking ballet lessons.

He's always promising to introduce me to the Queen.

I'm seeing Mary tomorrow.

We're having a great time, doing this show.