forms the infinitive of the third-conjugation verbs
From Old Galician-Portuguese -ir, from Latin -īre, the ending of the present active infinitive form of fourth conjugation verbs. In some verbs, it is a reflex of Latin -ere of the third conjugation.
Napisz to słowo
Ćwicz mówienie i zapamiętywanie " -ir " i wielu innych słów i zdań z portugalski .