Present perfect continuous

 Present perfect  continuous

this tense is used for an action that begun in the past and still going on

form: sub+have/has+been+main verb +ing +object

Sign: have/has+been+ing

Example

1.      I have been learning English for a years

2.      We have been living here since 1991

3.      How long have you been working for me?

4.      He has been teaching for twenty years

5.      They have not been ironing their clothes