Here is a review of how to use and form the imperative usted form: Commands are used when telling someone to do something, or ordering. This is referred to as the “imperative” form of the verb. For example:
Prepare usted la comida.
(you, formal) Prepare the food.
Cante usted la canción.
(you, formal) Sing the song.
Preparen ustedes la fiesta.
(you, pl. formal) Prepare the party.
Canten ustedes las canciones.
(you, pl. formal) Sing the songs.

Formal speech, or usted, is always used to be polite or to express respect for the person or group of people to whom you are speaking.
Coma usted la comida.
(you, formal) Eat the food.
Sirve (tú) la comida.
(you, informal) Serve the food.

The formal commands usted y ustedes are formed the same way as the present indicative:
Begin with the yo form of the present indicative.
Then drop the -o ending.
Finally, add the following endings:
-ar verbs:
-e (for usted), -en (for ustedes)
-er and -ir verbs:
-a (for usted), and -an (for ustedes)
Take a look at the following examples of -ar, -er, and -ir regular verbs.
Preparar: Prepare usted el dulce.
Comer: Coma usted la cereza.
Escribir: Escriba usted en el papel.
Another thing to keep in mind is that similar to regular verbs ending in -ar, -er, and -ir, irregular verbs have similar endings when using formal commands. For example:
dar
dé (usted)
dén (ustedes)
estar
esté (usted)
estén (ustedes)
ir
vaya (usted)
vayan (ustedes)
ser
sea(usted)
sean (ustedes)

Formación del presente perfecto
Would you like to be able to talk about things that happened in the past that may still be going on? The presente perfecto, or present perfect tense, can help you do this. To form the present perfect tense, use haber in the present tense then add the past participle of the verb. The present tense forms of haber are he, has, ha, hemos, habéis, han.
You then combine the present-tense form of haber with the past participle of the verb. To form the past participle, drop the infinitive ending (-ar, -er, -ir) and add an ending from the chart below.

For verbs ending in . . .
add . . .
-ar
-ado
-er
-ido
-ir
-ido

Now look at the following sentences using the present perfect of other Spanish verbs.
Hemos hablado con el Sr. Marquez
We have spoken to Mr. Marquez.
He decidido estudiar español.
I have decided to study Spanish.
Ha bailado toda la noche.
He/she has danced all night.

Sentences above is what i need help with