The present perfect is formed by combining the auxiliary verb "has" or "have" with the past participle.

I have studied.
He has written a letter to María.
We have been stranded for six days.

--------------------------------------------------------------------------------

Because the present perfect is a compound tense, two verbs are required: the main verb and the auxiliary verb.

I have studied.
(main verb: studied ; auxiliary verb: have)

He has written a letter to María.
(main verb: written ; auxiliary verb: has)

We have been stranded for six days.
(main verb: been ; auxiliary verb: have)

--------------------------------------------------------------------------------

In Spanish, the present perfect tense is formed by using the present tense of the auxiliary verb "haber" with the past participle. Haber is conjugated as follows:

he
has
ha
hemos
habéis
han

--------------------------------------------------------------------------------

The past participle is formed by dropping the infinitive ending and adding either -ado for -ar verbs, or -ido for -ir and -er verbs. Some past participles are irregular.

For a review of the formation of the past participle [click here].

The following examples all use the past participle for the verb "comer."

(yo) He comido.
I have eaten.

(tú) Has comido.
You have eaten.

(él) Ha comido.
He has eaten.

(nosotros) Hemos comido.
We have eaten.

(vosotros) Habéis comido.
You-all have eaten.

(ellos) Han comido.
They have eaten.

--------------------------------------------------------------------------------

When used as an adjective, the past participle changes to agree with the noun it modifies. However, when used in the perfect tenses, the past participle never changes.

Past participle used as an adjective:
La cuenta está pagada.
The bill is paid.

Past participle used in the present perfect tense:
He pagado la cuenta.
I have paid the bill.

Here's a couple of more examples:

Past participle used as an adjective:
Las cuentas están pagadas.
The bills are paid.

Past participle used in the present perfect tense:
Juan ha pagado las cuentas.
Juan has paid the bills.

Note that when used to form the present perfect tense, only the base form (pagado) is used.

--------------------------------------------------------------------------------

Let's look more carefully at the last example:

Juan ha pagado las cuentas.
Juan has paid the bills.
Notice that we use "ha" to agree with "Juan". We do NOT use "han" to agree with "cuentas." The auxiliary verb is conjugated for the subject of the sentence, not the object. Compare these two examples:

Juan ha pagado las cuentas.
Juan has paid the bills.

Juan y María han viajado a España.
Juan and Maria have traveled to Spain.
In the first example, we use "ha" because the subject of the sentence is "Juan." In the second example, we use "han" because the subject of the sentence is "Juan y María."

--------------------------------------------------------------------------------

The present perfect tense is frequently used for past actions that continue into the present, or continue to affect the present.

He estado dos semanas en Madrid.
I have been in Madrid for two weeks.

Diego ha sido mi amigo por veinte años.
Diego has been my friend for 20 years.

--------------------------------------------------------------------------------

The present perfect tense is often used with the adverb "ya".

Ya han comido.
They have already eaten.

La empleada ya ha limpiado la casa.
The maid has already cleaned the house.

--------------------------------------------------------------------------------

The auxiliary verb and the past participle are never separated. To make the sentence negative, add the word "no" before the conjugated form of haber.

(yo) No he comido.
I have not eaten.

(tú) No has comido.
You have not eaten.

(él) No ha comido.
He has not eaten.

(nosotros) No hemos comido.
We have not eaten.

(vosotros) No habéis comido.
You-all have not eaten.

(ellos) No han comido.
They have not eaten.

--------------------------------------------------------------------------------

Again, the auxiliary verb and the past participle are never separated. Object pronouns are placed immediately before the auxiliary verb.

Pablo le ha dado mucho dinero a su hermana.
Pablo has given a lot of money to his sister.

To make this sentence negative, the word "no" is placed before the indirect object pronoun (le).

Pablo no le ha dado mucho dinero a su hermana.
Pablo has not given a lot of money to his sister.

--------------------------------------------------------------------------------

With reflexive verbs, the reflexive pronoun is placed immediatedly before the auxiliary verb. Compare how the present perfect differs from the simple present, when a reflexive verb is used.

Me cepillo los dientes. (present)
I brush my teeth.

Me he cepillado los dientes. (present perfect)
I have brushed my teeth.

To make this sentence negative, the word "no" is placed before the reflexive pronoun (me).

No me he cepillado los dientes.
I have not brushed my teeth.

--------------------------------------------------------------------------------

Questions are formed as follows. Note how the word order is different than the English equivalent.

¿Han salido ya las mujeres?
Have the women left yet?

¿Has probado el chocolate alguna vez?
Have you ever tried chocolate?
Here are the same sentences in negative form. Notice how the auxiliary verb and the past participle are not separated.

¿No han salido ya las mujeres?
Haven't the women left yet?

¿No has probado el chocolate ninguna vez?
Haven't you ever tried chocolate?