Past Perfect Continuous Tense and Its Uses

The Past Perfect Continuous tense, also known as the past perfect progressive tense, is used to describe an action that started in the past and is still ongoing or has recently stopped. It is formed by using the auxiliary verb "had" followed by the verb "been" and the present participle of the main verb (the base form of the verb plus "-ing").

VERB: 1st + ing

HELPING VERB: Had been

For Example:

 

1. I had been studying for the exam all day. (The action of studying started in the past and is still ongoing.)
2. They had been working on the project for weeks. (The action of working on the project started in the past and is still ongoing.)

 

The structure of the Past Perfect Continuous tense is:

 

1) Simple: Subject + Helping Verb + Verb + Object

 

2) Negative: Subject + Helping Verb + not + Verb + Object

 

3) Interrogative: Helping Verb + Subject + Verb + Object

 

4) Negative Interrogative: Helping Verb + Subject + not + Verb + Object

There are several uses of Past Perfect Continuous Tense:

1. The past perfect continuous tense is often used to describe temporary situations or actions that are in progress for a specific period of time. It can also be used to emphasize the duration of an action. 

For Example:

 

1. I had been living in New York for three years. (The action of living in New York started in the past and is still ongoing.)
2. She had been feeling sick for the past few days. (The action of feeling sick started in the past and is still ongoing.)

2. It's important to note that the past perfect continuous tense is not used to describe completed actions or events. For those, you would use the present perfect tense. 

For Example:

 

1. I had finished my homework. (The action of finishing the homework is completed, so the present perfect tense is used.)
2. He had seen the movie twice. (The action of seeing the movie is completed, so the present perfect tense is used.)

Use of For and Since:

In the perfect continuous tenses (present perfect continuous, past perfect continuous, and future perfect continuous), the words "for" and "since" are used to indicate the duration of an action that has been or will be ongoing.

 

1."For" is used to describe a specific length of time. It is followed by a length of time, such as a number of days, weeks, months, or years. For example:

 

1. I had been waiting for three hours. (The action of waiting started in the past and has lasted for a specific length of time.)
2. They had been working on the project for six months. (The action of working on the project started in the past and lasted for a specific length of time.)
3. I had been studying for the exam for three hours by the time my tutor arrives. (The action of studying will have lasted for a specific length of time by a certain point in the future.)

2. "Since" is used to describe a specific point in time. It is followed by a specific time, such as a date, a day of the week, or a specific moment. For example:

 

1. I had been waiting since noon. (The action of waiting started at a specific point in time in the past and has continued up until now.)
2. They had been working on the project since Monday. (The action of working on the project started at a specific point in time in the past and continued up until some point in the past.)
3. I had been studying for the exam since this morning by the time my tutor arrives. (The action of studying will have started at a specific point in time in the past and will have continued up until a certain point in the future.)

I hope this helps! Let me know if you have any other questions.