The continuous aspect

be + present participle (verb-ing)

The continuous aspect is expressed with the auxiliary be and the present participle -ing form of the verb. Depending on the time of the action, we use one of the following forms of be: the past (was, were), present (am, are, is) or modal + infinitive (e.g. will be).

The continuous aspect focuses on the duration of an event. It expresses that the action was, is or will be in progress at a specific point in time or over a period of time. The point in time may be defined by a time expression (now, at 5 o'clock yesterday, this time tomorrow) or a clause (when I came home, when I come home). For the period of time, we can also use a time expression (all day yesterday) or a clause (while she was reading).

Examples of the continuous aspect:

Are you enjoying yourself? (now)
At 9 o'clock, I was sitting on the train.
When I came home, he was sleeping.
She must be waiting for me. (now)
Rob was hiking all day yesterday.
While she was reading, Bill was working on the computer.
In January, I'll be living at my brother's.