14 different verbs tenses are recognized by the Real Academia Española and any Spanish student will tell you, that’s a lot of conjugations!
In addition to various verb tenses, Spanish also has many (many) irregular verbs.
Some of those verbs are in the Present Tense and are called Stem-changing Verbs.
This means that the first vowel (indicated) in the first part of the verb (called the stem) changes to a vowel combination. Sounds confusing, I know. Let’s take a look at the first verb, Poder.
Poder- to be able to (can)
Yo puedo (I can) * Nosotros podemos (We can)
Tú puedes (You can) * Vosotros podeís (You all can)
Él puede (He can) Ellos pueden (They can)
* Notice the Nosotros and Vosotros forms DO NOT stem change, they conjugate normally using ‘o’ and not ‘ue’
Now, look at the purple, bold conjugations. Do you see the purple boot?
There are many stem-changing verbs in the Present Tense that conjugate just like this, where the Nosotros and Vosotros forms do not stem-change. I hope this helps and possibly answers some Spanish grammar questions!