The vast majority of my students in 10 years of teaching English have been Spanish speaking, mainly from Spain. Here are 3 common errors with regard to modal verbs. Modal verbs are verbs that most of the time are used to adapt the meaning of the verb that follows. The explanations below can also apply to students whose first language is not Spanish.
1. Modal verbs shouldn’t have a preposition after them:
Many students incorrectly say ‘he can to come at 8’ or ‘they must to go running this evening’. However, all modal verbs except for ‘ought to’ are followed by the base form of a verb (or infinitive) with no preposition after the modal. Some examples:
I should go to visit them.
I think it will rain tomorrow.
Things could have been better.
Someone may have seen them.
They might be home tomorrow.
They may be late.
They would have known if they had gone to the seminar.
He can come by anytime.
You must get that project finished.
I shall hand-in the paper on time.
2. Modals don’t have different tense forms like regular and irregular verbs:
Remember that modal verbs can’t be switched from tense to tense like normal verbs. For example, we cannot say ‘we musted do the homework’ or ‘I will must to study Norwegian’. In other words, they do not have a participle or a past form.
3. Modals cannot appear together:
Also, modal verbs cannot appear together in the same sentence. Many people say ‘I will can go out tonight’. This is very incorrect. Since ‘will’ and ‘can’ are both modal verbs we need to use ‘to be able to’ after ‘will’. So the correct sentence would be ‘I will be able to go out tonight’. This would translate in Spanish as ‘Yo podré salir esta noche’ and in French as ‘Je peux sortir ce soir’.