Here's why:
* Infinitives in Spanish end in "-ar", "-er", or "-ir". "Cantar" ends in "-ar".
* Infinitives are the base form of a verb. They are not conjugated and express the action or state of the verb without specifying tense, person, or number.
For example:
* Cantar (to sing) - Infinitive
* Canto (I sing) - First person singular present indicative
* Cantamos (we sing) - First person plural present indicative
Let me know if you have any other questions!