Happening up to This Moment
Present Perfect Continuous
The present perfect continuous places the emphasis on the duration of a current activity. It is used to express either when an action in progress began, or the length of an action in progress. The present perfect continuous is never used with stative verbs.
Example:
I've been trying to schedule this project since last quarter.
They've been arguing about how to unpack this shipment for two days!
She hasn't been stocking the parts we need this month.
Positive Form:
Subject + have + been + 'ing' form of verb + (object(s)) + since / for + time expression
I've been trying to schedule this project since last quarter.
Negative Form:
Subject + have + not + been + 'ing' form of verb + (object(s)) + since / for + time expression
She hasn't been stocking the parts we need this month.
Question Form:
(Question Word) + have + subject + been + 'ing' form of verb?
How long has the consultant been planning to test our assembly line?
Examples of What Caused Something
The present perfect continuous is often used to express the action that caused a present result.
Example:
He's been nervous about industrial espionage since he heard the rumor. That's why he can't quit smoking!
I've been calculating our total output since midnight. That's why I'm almost finished with the report.
Present Perfect Contrasted with Present Perfect Continuous
The present perfect and present perfect continuous are both used to express the duration of an activity that begins in the past and continues into the present. Either form is used with general activities, although the use of the present perfect continuous can indicate that an activity is about to change. The present perfect continuous describes the duration of a current activity and tends to be used with more specific action verbs.
Example of Present Perfect:
The fixed manufacturing costs have been set at the same level for a decade.
He has been waiting to reach the time fence for three weeks and now is enforcing the new policy.
Example of Present Perfect Continuous:
He's been nervous about industrial espionage since he heard the rumor. That's why he can't quit smoking!
I've been studying the damage done in the process of completion since January.
When emphasizing the duration of the current action, use the present perfect continuous.
Example:
They've been arguing over how to convert the industrial area after collapse for months.
They've been arguing about how to unpack this shipment for two days!
The present perfect continuous conveys the length of an activity, whereas the present perfect can also be used to relate the quantity, or amount finished up to the present moment in time.
Example:
I've communicated with three companies who want us to make on request.
I've compiled a list of every forecast error our consultant has made over the last four years.