"Mother" and "father" in Spanish?	La madre, el padre. Informally: mamá, papá (with the accent on the last syllable).
"Parents" in Spanish?	Los padres. False friend: los parientes means relatives, not parents.
"Son" and "daughter" in Spanish?	El hijo, la hija. Los hijos means sons, or children of either sex.
"Brother" and "sister" in Spanish?	El hermano, la hermana. Los hermanos means brothers, or siblings.
"Grandfather" and "grandmother" in Spanish?	El abuelo, la abuela. Los abuelos means grandparents.
"Grandson" and "granddaughter" in Spanish?	El nieto, la nieta. Los nietos means grandchildren.
"Uncle" and "aunt" in Spanish?	El tío, la tía. Mis tíos can mean my uncles, or my aunt and uncle.
"Cousin" (male and female) in Spanish?	El primo, la prima.
"Nephew" and "niece" in Spanish?	El sobrino, la sobrina.
"Husband" and "wife" in Spanish?	El esposo, la esposa. Also el marido and mi mujer, which are very common in Spain.
"Boyfriend" and "girlfriend" in Spanish?	El novio, la novia. The same words mean groom and bride at a wedding.
"Father-in-law" and "mother-in-law" in Spanish?	El suegro, la suegra. Los suegros means parents-in-law.
"Brother-in-law" and "sister-in-law" in Spanish?	El cuñado, la cuñada.
"Stepfather" and "stepmother" in Spanish?	El padrastro, la madrastra.
"I'm an only child" in Spanish?	"Soy hijo único" (male) / "Soy hija única" (female).
"Twins" in Spanish?	Los gemelos / las gemelas. Many speakers use mellizos for non-identical twins.
"Man, woman, boy, girl" in Spanish?	El hombre, la mujer, el niño, la niña. Mujer also means wife in many regions.
"Baby" in Spanish?	El bebé. In much of Latin America, la bebé is used for a baby girl.
"Friend" (male and female) in Spanish?	El amigo, la amiga. "Mi mejor amiga" means my best friend.
"Neighbour" in Spanish?	El vecino, la vecina. "Mis vecinos son muy simpáticos."
"How many brothers and sisters do you have?" in Spanish?	"¿Cuántos hermanos tienes?" Answer: "Tengo dos hermanos y una hermana."
"My family lives in Lima" in Spanish?	"Mi familia vive en Lima." La familia is singular, so the verb is singular too.
"I'm married" in Spanish?	"Estoy casado" (male) / "Estoy casada" (female). Divorced: divorciado/a. Single: soltero/a.
"My older brother" and "my younger sister" in Spanish?	Mi hermano mayor, mi hermana menor. Mayor and menor go after the noun.
"To get along well with" in Spanish?	Llevarse bien con. "Me llevo bien con mi hermana."