The present continuous tense is used to show an activity that is in progressing or not complete at the time of speaking. The activity started in the past and will go into the future.
The present continuous tense of any verb is formed with the auxiliary verb to be (am, is, are, was, were) and the present participle of the main verb (verb + ing). The auxiliary verb varies according to the person used with the present continuous tense.
We use the present continuous tense:
for an action that is still happening at the time of speaking.
for an action in the future without specifying when.
to talk about a planned or an arranged action that is to take place at a particular time in the future.
for an action that is going on but not necessary at the time of speaking.
for a changing or evolving situation.
to describe a repeated action that the speaker finds irritating.
with an adverb such as always, constantly, forever, etc to describe an action that happens many times or frequently.
There are main verbs, generally action verbs that are not normally used in the present continuous tense. These are verbs of perception, verbs used with the five senses, or verbs used to describe states.
In questions, the auxiliary to be (am/is/are/was/were) comes before the subject, and the subject is followed by the present participle of the main verb (am/is/are/were + subject + verb-ing).
In answer to question, the auxiliary verb is commonly used without the main verb.
We use the present continuous tense in the following ways.