Learn Hardcore Spanish (Latin America): Tengo nueve libros verdes en mi mochila.

In Spanish most descriptive adjectives follow the noun they modify. So you say libros verdes (literally “books green”) instead of verde libros. This order can change emphasis or style, but the standard pattern is noun + adjective.

Why does verdes end in -es rather than -e?

Adjectives in Spanish must agree in gender and number with the noun. Here libros is masculine plural, so verde (singular) takes an -s to become verdes (plural). If it were one green book, you’d say libro verde.

Why do we use tengo instead of tienes or tiene?

Tengo is the first-person-singular form of tener (“to have”), so it means “I have.”

tienes = you have (informal, tú)
tiene = he/she has or you have (formal, usted)

Why is nueve placed before libros?

Cardinal numbers in Spanish typically come right before the noun they count, just as in English: nueve libros = “nine books.” You wouldn’t say libros nueve.

Could I say los nueve libros verdes en mi mochila instead of tengo nueve libros verdes en mi mochila?

If you start with los, you’re referring to a specific set already known: Tengo los nueve libros verdes en mi mochila = “I have the nine green books in my backpack” (you both know which nine). Without los, you’re just stating quantity, not pinpointing a particular group of books.

Why do we say en mi mochila instead of using a or adding an article?

en expresses location (“in” or “on”).
You don’t use an article before a singular possessive adjective in Spanish. So it’s mi mochila, not la mi mochila.
If you wanted “in a backpack,” you’d say en una mochila.

Is it correct to move en mi mochila to the front, as in En mi mochila tengo nueve libros verdes?

Yes. Spanish word order is flexible. Fronting en mi mochila shifts emphasis to the location:
“In my backpack I have nine green books.”

Can I drop mi or nueve and still be grammatically correct?

You can omit elements if context allows, but you’ll change or lose information:

Drop nueve → Tengo libros verdes en mi mochila (“I have green books in my backpack,” unspecified number).
Drop mi → You’d need an article or different possessive:
• en una mochila = “in a (one) backpack”
• en la mochila = “in the backpack”
Simply saying en mochila is ungrammatical.

Why isn’t there an accent mark on mi in mi mochila?

Mi (without accent) is the possessive adjective “my.”
Mí (with accent) is the prepositional pronoun “me” after certain prepositions (e.g., “para mí” = “for me”). They’re two different words, so the accent distinguishes them.