PRESENT PERFECT

Present perfect continuous it is a time that us is in use for saying principally to actions that they began in the past and that in the present moment they continue developing.Also it is in use for actions that began in the past and that they have just finished. Present perfect continuous he is formed with the auxiliary to be in his form of present perfect , more the gerund of the principal verb.The negative form is formed with present perfect of the auxiliary verb in his negative form, and the interrogative form is constructed using present perfect of the auxiliary verb in his interrogative form, more the gerund of the principal verb.