16.5.4 Sequence of personal pronouns with modals oder auxiliaries
Modal verbs were already discussed in the chapter about the present tense. They do not tell anything about an activity itself, but about the relation between the subject and the activity (described by the full verb).
You must pay.
You shall pay.
You can pay.
You may pay.
In English the sequence of pronouns is not depending on the number of verbs in a clause. The rule for putting a pronoun in English is quite complicated.
You give Marythe keys.
You give the keys toMary. (both is possible)
You give her the keys.
You give the keys to her. (both is possible)
You give themto Mary. => not possible: You give Mary them.
You give them to her. => not possible: You give her them. / You give them her.
A basic rule is: as longs as the accusative/direct object is not substituted with a pronoun, the sequence of pronouns is interchangeable. If the accusative/direct object is substituted with a pronoun, then this pronoun is to be put before the dative/indirect object, which is attached with the preposition to. The position is always after the verbs.
In French the pronoun(s) are always before the first conjugated verb, but before the infinitive. Let's have closer look at this rule.