Compartes is the conjugation of the verb compartir for the second person singular in the simple present. The simple present tense is used to talk about habitual actions or routines. So in this very moment you share lunch with your friend. In this sentence, el is the masculine singular definite article and accompanies the masculine singular noun almuerzo.
Tú compartes el almuerzo con tus amigos
Corre is the conjugation of the verb correr for the second person singular usted (formal you) in the simple present. The formal you is used when addressing a person in a polite way. So if you want to show respect for a person, you can talk using this way. So this person can be your boss, your teacher or an old person. Finally:
Usted corre los viernes
Vive is the conjugation of the verb vivir for the third person singular in the simple present. In this way, nuestro abuelo can be replaced by the subject pronoun that matches the third person singular, which is él. Nuestro belongs to the long-form possessive adjectives. Possessive adjectives are used to indicate ownership or possession. The long-form is used to emphasize the owner of something.
Describen is the conjugation of the verb describir for the third person plural in the simple present. In this way, los turistas can be replaced by the subject pronoun that matches the third person plural, which is ellos. The word los is the definite article that matches the masculine plural form. This is used here because turistas is a noun that also matches the masculine plural form.
Leemos is the conjugation of the verb leer for the first person plural in the simple present. In this way, Tomás y yo can be replaced by the subject pronoun that matches the first person plural, which is nosotros. On the other hand, the word unos is the indefinite article that matches the masculine plural form. We use it here because libros is a noun that also matches the masculine plural form.
