Present perfect continuous

Use the Present perfect continuous  to state something started in the past and has just ended or to express annoyance about something, started in de past.
The present perfect continuous consists of:
have/has + been + verb in -ing form.

Examples

• John has been studying for years to become lawyer.
• I have been waiting for three hours.
• We have been drinking tea.

The following signal words can indicate that the present perfect continuous should be used:

• all day.
  I have been working all day.
• since.
  I have been waiting since 4 o’clock.
• for.
  I have been sleeping for three hours.
• how long. (in questions)
  How long has Boris been learning English?

The present perfect continuous can also be used in question and negative sentences.

• She has been talking on the phone.
  Has she been talking on the phone?
  She hasn't been talking on the phone.
• They have been swimming in the lake.
  Have they been swimming in the lake?
  They haven't been swimming in the lake.