More on Personal Pronouns

Singular

Plural

Yo = I

nosotros = we (masc.)
nosotros = we (fem.)

tú = you (informal)

vosotros = you (masc., inf.)
vosotras = you (fem., inf.)

usted = you (formal)

ustedes = you (formal)

él = he

ellos = they (masc.)

ella = she

ellas = they (fem.)

Attention:
It is not necessary to use the personal pronouns since the verb form itself often tells you who the subject is. However, personal pronouns are used in certain situations to add emphasis or clarify the subject.

¿Es ella la profesora?
Sí, es la profesora.
Attention:
The form is used to address friends, children, coworkers and relatives. Young people use it predominantly with each other even if they have just met. Usted is used to show respect. For example, Spanish speaking students use the usted form with their professors but the form with each other. If unsure, use usted.
Attention:
The pronouns nosotros, vosotros, ellos have masculine ("-os") and feminine ("-as") forms. The masculine form can refer to groups of males only or to groups of males and females together. The feminine form refers only to groups of females. The vosotros form is used only in Spain. In the rest of the Spanish speaking world, ustedes is used for in informal and formal address.