Present Perfect continuous....
In present perfect continuous tense continuous or on going actions are expressed that are continuous until now.
There will be time reference e.g. since 1847 or for two hours etc.
Use of "since"....
Since will be used when only starting time of an action is given and no ending time is known.
e.g since 1999, since morning, since evening etc.
This concept will be explain more clearly in further examples.
Use of "for"....
For will be used when total time of an action is given with ending time is known.
e.g for two hours, for six days, for one year etc.
This concept will be explain more clearly in further examples.
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Passive Sentences...
Structure...
Object + helping verb + First form of Verb( with "ing" ) + object + time reference.
In these sentences "have been" ( with I, you, they , we, plural name etc) or "has been" (with he, she, it, singular name etc) is used as helping verb.
First form of verb with "ing" .
Time reference is necessary for present perfect continuous tense because if we do not use time reference it will simple present continuous tense.
Example...
- Sara has been going to school since 2012.
Here we used...
"Has been" because "Sara" is a singular name.
"Since" because "2012" is only starting time.
- Sara has been going to school for five years.Here we used "for" because " five years" is complete time.
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Negative Sentences...
Structure...
Object +has not been/have not been + First form of Verb( with "ing" ) + object + time reference.
In these sentences "have not been" ( with I, you, they , we, plural name etc) or "has not been" (with he, she, it, singular name etc) is used as helping verb.
First form of verb with "ing" .
Example...
- Sara has not been going to school since 2012.
Here we used...
"Has not been" to make the sentence negative.
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Interrogative Sentences...
Structure...
Has/ have + Object + been + First form of Verb( with "ing" ) + object + time reference?
In these sentences ...
"have " ( with I, you, they , we, plural name etc) or "has " (with he, she, it, singular name etc) is used at the start of sentence.
First form of verb with "ing" .
Question mark (?) at the end.
Example...
- Has Sara been going to school since 2012?
Here we used...
"Has " at the start of sentence to make the sentence interrogative.
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Some more examples...
- We have been doing our work for three months.
We have not been doing our work for three months.
Have we been doing our work for three months?
- Sara and Ali have been writing a story since morning.
Sara and Ali have not been writing a story since morning.
Have Sara and Ali been writing a story since morning?
- You have been teaching since 1994.
You have not been teaching since 1994.
Have you been teaching since 1994?
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