3.

The progressive (or continuous) aspect indicates a continuous, ongoing action or event. In English, this is expressed morphologically through:

the addition of the suffix -ed to the verb stem, which is then used with the auxiliary `to have.'

the addition of the suffix -ing to the verb stem, which is then used with the auxiliary `will.'

the addition of the suffix -ed to the verb stem, which is then used with the auxiliary `to be.'

the addition of the suffix -ing to the verb stem, which is then used with the auxiliary `to have.'

the addition of the suffix -ing to the verb stem, which is then used with the auxiliary `to be.'