Answer:
1. es; feminine, singular
2. es; masculine, singular
3. son; masculine, plural
Step-by-step explanation:
Yo-soy (singular, depends on gender)
tu- eres (singular, depends on gender)
el/ella/usted (singular, masculine/feminine/depends)
nosotros/nosotras (plural, mascine/feminine)
vosotros/vosotras (plural, mascine/feminine)
ellos/ellas/ustedes (plural, masculine/feminine/depends)