In English the adjective is placed before the noun,

In Spanish, more often than not, they are placed after the noun.

Adjectives must show agreement of gender (masculine, feminine) and  number (singular or plural) with the person or thing
they describe.

Singular Spanish Adjectives
Some examples are;         

(1) la puerta verde = the green door
(2) el coche azul= the blue car.
(3) el es inglés = he is English.
(4) ella es inglesa= she is English.

Plural Spanish Adjectives   
If the noun is in the plural form the adjective must conform and by also taking the plural form.

Remember that to make a noun plural; —-

Nouns that end in a vowel, (a,e,i,e,u) ——- add an "s" to the end.
Nouns that end in a consonant, (b,c,d,f)  —- add ‘es’ to the end

The adjective follows the same rules’

Adjectives that end in a vowel,—— add an ’s to the end.
Adjectives that end in a consonant,—add ‘es’ to the end.

Examples are;  

(1) las puertas verdes = the green doors.
(2) los coches azules =  the blue cars.
(3) ellos son españoles = they are English. (masc’)
(4) ellas son españoles = they are English. (fem’)

The following always go after the noun; colours and nationalities

for example;

(1) el barco rojo  =  the red boat.
(2) la flora amarilla  =  the yellow flower.
(3) el hombre español  =  the Spanish man.
(4) la mujer inglesa  =  the English lady.

There are some adjectives that are neutral and they also go after the noun.

for example;

feliz (happy), triste (sad), elegante (elegant), facil (easy), difícil (difficult/hard).

(1) el/ella está feliz = he/she is happy, (singular).
—-ellos/ellas están felices = they are happy, (plural, note that ‘z’ changes to ‘c’).
(2) el/ella está triste = he/she is sad, (singular).
—-ellos/ellas están tristes = they are sad, (plural).
(3) el/ella está  elegante =  he/she is, (singular).
—-ellos/ellas están  elegantes = they are elegant, (plural).
(4) eso está fácil = this is easy, (singular).
—-esos están fáciles = these are easy, (plural).
(5) esta está difícil = that is difficult / hard, (singular).
—-estas están difíciles = those are difficult / hard, (plural).

When malo or bueno are placed before the noun they change to mal and buen.

Examples are;

(1) una pelicula mala, or, una mala pelicula. ( a  good film).

(2) un tiempo malo, or,  un mal tiempo. ( a bad time).

(3) una buena niña, or, una niña buena

(4) un niño bueno, or, un  buen niño, (a good boy)

Spanish Adjectives with double meaning

The adjective ‘grande’ (large,big), can go before the noun as well as after, but it has two distinct meanings.

After the noun it means large/big in size. This is the normal place that you would expect ‘grande’ to be.

Before the noun it means large in status.

With the masculine, singular noun form,

Examples are;

(1) el es un hombre grande = he is a big or large man, (adjective after the noun), ‘grande’ is normal.

(2) el es un gran hombre = he is a great man. (adjective before the noun),’grande’ changes to ‘gran’.

In their plural forms, grande becomes ‘grandes’ and is used in both cases.

Examples are;

(3) los hombres grandes = the big or large men.

(4) los grandes hombres = the great men.

In the feminine forms, singular and plural nouns, ‘grande’ does not change its form.

Examples are;

(1) la estatua grande = the big or large statue.

(2) las estatuas grandes = the big or large statues.

(3) la grande estatua = the great statue.

(4) las grandes estatuas = the great statues.

The following always go before the Spanish noun;

(a lot) = mucho, muchos, (masculine), mucha, muchas, (feminine).

(other) = otro, otros,(masculine), otra, otras, (feminine).

Some examples are;

(1) el tiene mucho dinero  =  he has a lot of money.

(2) el compra muchos libros  =  he is buying a lot of books.

(3) el hace mucha sopa  =   he is making a lot of soup.

(4) el vende muchas camisas  =   he sells a lot of shirts.

Spanish Possessive Adjectives

The singular form is;

mi = my; tu = you; su = his,hers,it’s.

The plural form is;

nuestro = our; vuestro =your; su = their.

Examples are;

(1) mi habitatión es la número 20 = my room is number 20.

(2) su habitatión es la número 15 = his/her room is number 15.

(3) su pasaporte, por favor = your passport, please.

(4)  nuestro hotel = our hotel.

When the noun following the possessive adjective is in the plural,

the possessive adjective must also take the plural form.

Examples are;

(1) mis amigos = my friends.

(2) Sus pasaportes = their passports.

(3) nuestras habitaciones = our rooms.

Notice that nuestro and vuestro also change their endings,—-

depending on the gender of the noun which follows.

Examples are;

(1) nuestra habitatión ( fem’, la) = our room.

(2) nuestro amigo (masc’, el) = our friend.

(3) vuestra casa (fem’, la) = our house.

(4) vuestro coche (masc’, el) = your car.