Not all verbs require a function word in Portuguese, but some do.

These verbs require the use of the reflexive pronoun, appropriate to the subject.

However, other verbs require an additional suffix to shift classes.

The verbs forego and forgo (the style book will tell you the difference) do not require an "e" at the end.

This impersonal verb requires a direct object noun phrase.

Even these few verbs require an auxiliary to conjugate other tenses besides the present and simple past.

Some verbs require the genitive case to be used.

Some verbs require the use of a reflexive pronoun.

Also, verbs can require an object to use the vocative case.

Different verbs will require different kinds of predicate/argument structure.