Study materials
These sentences differ only in the form of the verb, but the meaning is different.
I think you're right.
An opinion, a state.
I'm thinking about your offer.
An action.
You're always leaving the door open!
A complaint.
This article explains which verbs do not take the continuous form, which verbs have two meanings, the difference between he is rude and he is being rude, and always with the continuous.
State verbs in the continuous
State verbs name a state, not an action: knowledge, opinion, feeling, possession. They include know, believe, understand, like, want, need, own, belong, seem. They do not take the continuous, so people say I know, not I'm knowing.
A few verbs, though, have two meanings. In one they name a state, in the other an action, and then the continuous is possible.
| State, simple form | Action, continuous form | What changed |
|---|---|---|
| I think you're right. | I'm thinking about it. | opinion versus considering |
| She has a car. | She's having lunch. | possession versus an action |
| I see what you mean. | I'm seeing the doctor at five. | understand versus meet |
| The soup tastes salty. | The chef is tasting the soup. | a quality versus an action |
| The box weighs ten kilos. | She is weighing the box. | weight versus weighing |
Be is a special case. He is rude describes a character trait. He is being rude describes behaviour right now, and it is often a judgement or a reproach.
He is generous.
He is a generous person.
He is being generous today.
He is acting generously today, though he usually doesn't.
Always with the continuous
Always with the simple form names frequency. Always, constantly or forever with the continuous adds the speaker's emotional judgement. Most often this is irritation, sometimes approval.
He always takes the bus.
Just a habit.
He's always losing his keys!
A complaint.
She's always helping the neighbours.
Approval.
Content and intonation decide which. So in a formal reference, where ambiguity is unwelcome, the simple form is safer. Always goes between be and the -ing form: is always losing.
Common mistakes
The first mistake is the continuous form of a state verb.
I'm knowing the answer. → I know the answer.
Know describes a state.
The second mistake is the position of always.
She always is losing her keys. → She is always losing her keys.
Always comes after be.
The third mistake is the continuous form where a property is meant.
The suitcase is weighing twenty kilos. → The suitcase weighs twenty kilos.
Weight is a property, not an action.
The first mistake shows in the verb itself. Know, like, want, own and other state verbs have no continuous form. The second shows next to be. Always comes after it, before the -ing form. The third shows if you ask whether this is an action. Weigh meaning have a weight describes a property, so it takes the simple form.