with stem-changing verbs the stem often does not change for
With stem-changing verbs, the stem often does not change for all forms except for the "boot" or "shoe" forms (also known as the irregular forms) in present tense conjugation. The irregular forms are called "boot" or "shoe" forms because they have a change in the vowels in the middle of the word, resembling the shape of a boot or shoe.
To determine which verbs might have stem changes, you can start by looking at the infinitive form of the verb. If the infinitive ends in -ar, -er, or -ir and there is a vowel before the ending, there is a possibility for stem change.
For example, let's take the verb "pensar" (to think) as an example. The stem of the verb "pensar" is "pens-". In most forms, the stem remains the same, but in the "boot" or "shoe" forms (such as "yo pienso" meaning "I think" or "él/ella piensa" meaning "he/she thinks"), the letter "e" changes to "ie".
To conjugate the verb "pensar" in present tense, you would follow these steps:
1. Drop the -ar ending to get the stem "pens-".
2. For most forms, simply add the appropriate ending for the subject: "yo pienso", "tú piensas", "él/ella piensa", "nosotros pensamos", "vosotros pensáis", "ellos/ellas piensan".
So, in summary, with stem-changing verbs, the stem often does not change for most forms except for the "boot" or "shoe" forms in present tense conjugation. To identify these verbs, look for ones that have a vowel preceding the -ar, -er, or -ir ending in the infinitive form.