The simple tenses—present, past, and future—and the perfect tenses—present, past, and future—all have a progressive form used to express a continuing action. A progressive verb is formed by joining a form of be (present, past, or future) and the present participle of a verb.

The present progressive tense is formed by adding am, is, or are to the present participle of a verb (usually the present form + ing): am exploring, is running, are dreaming.

The past progressive tense is formed by adding was or were to the present participle: was working, were helping.

The future progressive tense is formed by adding will be to the present participle: will be studying.