Word order with modal verbs in complex tenses?

Question

If in the present tense I can simply say, *Ich kann kommen* (no double infinitive), why can't I follow the same rule when I use the future tense, and say, *Ich werde können kommen*? Why do I have to say (at least according to my grammar), *Ich werde kommen können*? Why this reversal that is, as far as I know, typical of the perfect tenses, where the characteristically German double infinitive is actually used: *Ich habe kommen können*, for *I have been able to come*, instead of the *Ich habe gekonnt kommen*.

Answer 1

Hello,

The word order for modal verbs in present tense is always:

We conjugate the modal verb and the infinitive of the main verb goes at the end of a sentence.

Ich kann kommen.

Ich kann ins Kino gehen.

Future tense in German is built with werden and infinitive. Here our conjugated verb is werden than infinitive of the main verb and afterwards the modal verb.

So for example:

Ich werde kommen können

Ich werde ins Kino gehen können

Ich habe kommen können - I could come

Ich konnte kommen - I have been able to come