2 kinds-

subject and verb

noun and adjective

Subject and Verb-Conjugation

You conjugate a verb to make it MATCH the subject.

Examples:

Yo form of SER is SOY, not eres

Nosotros form of TENER is TENEMOS, not tengo

Noun and Adjective-Agreement

Nouns and adjectives must AGREE in GENDER and in NUMBER.

*Masculine/Feminine, Singular/Plural*

Examples:

el libro blanco-masculine singular

los libros blancos-masculine plural

la mochila roja-feminine singular

las mochilas rojas-feminine plural