Stative and dynamic uses of verbs
The meaning expressed by a verb in present or past tense depends to a great extent on whether the verb refers to a single constant state, as in I know Tim’s email address, or to a dynamic occurrence, as in He goes to work by train.
More exactly, the meaning depends on whether the verb is being used statively or dynamically, since many verbs lend themselves to both interpretations. ‘Have’ usually refers to a permanent state, as in cats have sharp claws, but it also has dynamic uses as in have breakfast.
In general, dynamic but not stative senses can occur with the imperative and progressive, and after do in wh-cleft sentences:
Have breakfast! We are having breakfast. What we did was have breakfast.
*Have claws! *Cats are having claws *What cats do is have claws.
We refer to the present tense as the ‘simple Present’, more exactly as the ‘non-progressive Present’. The Progressive, consisting of a form of be + -ing, combines with tense to encode a single event observed in the process of happening. There is a meaningful distinction – and an obligatory choice in English – between expressing a situation by means of the Present tense alone and expressing it by the Present Progressive. Compare:
The sun doesn’t shine every day in Brussels, (non-Progressive Present)
but it is shining today. (Progressive Present)
