Fashion trends are always evolving. To describe ongoing situations, Portuguese uses an auxiliary verb (like estar or andar) followed by the preposition a and an infinitive. To describe something developing gradually, it pairs the auxiliary ir with a gerund (ending in -ando, -endo, or -indo). When using object pronouns with these verbal complexes, their placement depends on the type of sentence.
Pronouns in Affirmative Sentences
In affirmative sentences, you have two choices for object pronouns. You can attach them to the end of the main verb with a hyphen:
Or, you can attach them directly to the auxiliary verb:
Direct Objects and Infinitives
Attaching a direct object pronoun (o, a, os, as) to the end of an infinitive triggers a spelling change: the final -r drops, the pronoun gains an l (-lo, -la, -los, -las), and the verb's final vowel takes an accent (like -á or -ê).
Trigger Words
Negative words (like não, nunca, or ninguém) act as magnets. They force the pronoun to jump immediately before the auxiliary verb, without a hyphen.
You can see both the affirmative and negative rules at work when contrasting two different clauses. Notice how the pronoun attaches to the auxiliary in the affirmative half, but jumps in front of it after the negative trigger word: