In this article, we’ll cover the first group.
Common verbs ending in -AR include falarto speak, pensarto think and amarto love.
When the conjugation is regular, the endings of conjugated -AR verbs follow the same pattern. Below, we’ll use falarto speak in the present tense as an example:
Notice that the verb stem, (the beginning of the verb to which you add the respective ending), ends right before the last vowel of the verb (in its infinitive form). So, the stem of viajar is viaj-, and the stem of estudar is estud-. The stem of the verb anunciar would be anunci-.
Regardless of whether you’re conjugating a regular verb in its present tense, as in the above examples, or any other tense, you will always take the same verb stem and add on the appropriate ending.
The first person singular of every single regular verb always ends with just an o, so that’s the easiest one to memorize. You’ll confirm this as you read about the other verb groups.