256. The progressive form is a verb-phrase made by prefixing to the present participle some form of the verb to be.
| Active Voice | Present Tense |
|---|---|
| SINGULAR | PLURAL |
| 1. I am striking. | 1. We are striking. |
| 2. Thou art striking. | 2. You are striking. |
| 3. He is striking. | 3. They are striking. |
So in the other tenses:
| Past | I was striking, etc. |
|---|---|
| Future | I shall be striking, etc. |
| Perfect | I have been striking, etc. |
| Pluperfect | I had been striking, etc. |
| Future perfect | I shall have been striking, etc. |
| Present | I am being struck, etc. |
|---|---|
| Past | I was being struck, etc. |
257. In the passive, the progressive forms are confined to the present and the past tense.
- He is being helped by his brother. [Present.]
- I am being trained by Arthur Ray. [Present.]
- When I called, tea was being served. [Past.]
258. In subordinate clauses, the verb is (in its various forms) with its subject is often omitted in progressive phrases.
- While waiting for the train, I bought a newspaper. [That is, While I was waiting.]
- Though [he was] swimming vigorously, he could not stem the tide.
- When [I am] reading, I like to have the light shine over my left shoulder.
In parsing, the omitted words should be supplied.