Answer: 1. The endings for stem-changing verbs in Spanish are similar to the endings you have already learned, but they have some changes in certain forms. For example, in the present tense, the "o" in the stem changes to "ue" in some forms. Let me give you an example:
Regular verb: hablar (to speak)
- Yo hablo (I speak)
- Tú hablas (You speak)
- Él/Ella habla (He/She speaks)
- Nosotros hablamos (We speak)
- Ustedes hablan (You all speak)
- Ellos/Ellas hablan (They speak)
Stem-changing verb: poder (to be able to)
- Yo puedo (I can)
- Tú puedes (You can)
- Él/Ella puede (He/She can)
- Nosotros podemos (We can)
- Ustedes pueden (You all can)
- Ellos/Ellas pueden (They can)
2. In stem-changing verbs, the forms inside the "boot" (the forms that have the stem change) are affected. In the case of "o to ue" stem-changing verbs, the forms with the "o" in the stem change to "ue." For example, in the verb "poder," the "o" changes to "ue" in the forms "puedo," "puedes," "puede," "podemos," "pueden."
3. Here are three original sentences correctly conjugating "poder" (to be able to) with different subjects:
- Yo puedo nadar muy rápido. (I can swim very fast.)
- Tú puedes hablar español con fluidez. (You can speak Spanish fluently.)
- Él puede correr maratones sin problema. (He can run marathons without a problem.)
4. The main difference between a regular verb and a stem-changing verb in Spanish is that stem-changing verbs have a change in the stem in certain forms. Regular verbs, on the other hand, do not have this change. Stem-changing verbs follow a specific pattern where a vowel in the stem changes to a different vowel in certain forms. This change affects the pronunciation and spelling of the verb. Regular verbs, however, follow the usual conjugation patterns without any changes in the stem.
5. Stem-changing verbs are sometimes called "boot verbs" because if you graph the conjugation of these verbs on a chart, it forms a boot shape. The stem-changing verbs have a pattern where the forms in the "boot" (the stem change forms) deviate from the regular conjugation pattern. The stem-changing verbs are named so because the pattern resembles the shape of a boot. It's a visual way to help students remember and recognize these specific verbs and their conjugation pattern.