The Present Perfect Continuous Tense

One of my intermediate level classes recenly practiced the present perfect continuous tense. This is used for activities that began in the past and are continuing now, so you can't apply it to every situation, but it's very popular in conversation.

I have been teaching English for the last 20 years.

In the example above, the activity (teaching) started 20 years ago and has continued nonstop up to this moment in time.

Nadia has been working at that bakery since last August.

They've been eating a lot of potatoes lately.

We've been preparing for the holidays since November. �