In Tagalog grammar, the infinitive form of a verb is the base, unconjugated form of the verb, typically used to express what is commonly known as “to do” something. Tagalog verbs are morphologically complex, and their infinitive forms often appear at the beginning of verb phrases. Various affixes are added to this basic form to express aspects such as focus, aspect, voice, and others. Mastering infinitive forms is crucial in learning Tagalog as it serves as a foundation for verb conjugation and sentence construction.