Answer: e → i stem-changing verb
Explanation:
In spanish grammar a verb in infinitive has two parts:
-The ending: ar, er, ir
-The stem, which is everything else (except the ending, of course)
For example, the Spanish verb<em> servir (to serve):</em>
The <u>ending</u> is ir
The <u>stem</u> is serv
Now, some Spanish verbs change their stem in a predictable way when they are conjugated. These are called stem-changers or stem-changing verbs. In this sense, <u>there are three basic different ways in which the stem of a verb can change in the present tense:</u>
From <u>e</u> to <u>ie</u>
From o to ue
From <u>e</u> to <u>i</u>
Now for the verb <em>servir (to serve)</em>, we are talking about the third case (From <u>e</u> to <u>i</u>). Let's prove it:
1st person singular Yo: <u>si</u>rvo
2nd person singular (informal) Tú: <u>si</u>rves
2nd person singular (formal) Usted: <u>si</u>rve
3rd person singular El/Ella/eso/esa: <u>si</u>rve
1st person plural Nosotros: servimos
2nd person plural Ustedes (In latinAmerica): <u>si</u>rven
2nd person plural Vosotros (In Spain): servís
3rd person plural Ellos/Ellas: <u>si</u>rven
Note that in a stem‐changing verb all forms of the verb will undergo a stem change except for nosotros/nosotras (we) and vosotros/vosotras (you).
