My grandfather could play golf very well.Ĭlick here to find out more about ability.We use 'can' and 'could' to talk about a skill or ability. £200 for two cups of coffee!Ĭlick here to find out more about probability. It's snowing, so it must be very cold outside.We often call these 'modals of deduction' or 'speculation' or 'certainty' or 'probability'. Probability:įirst, they can be used when we want to say how sure we are that something happened / is happening / will happen. Here's a list of the modal verbs in English: canġ: They don't use an 's' for the third person singular.Ģ: They make questions by inversion ('she can go' becomes 'can she go?').ģ: They are followed directly by the infinitive of another verb (without 'to'). Click here to download this explanation as a pdf.Ĭlick here for all the exercises about modal verbs