Study materials
Two sentences with the same content. The second is three words shorter.
Because she felt tired, she left early.
Feeling tired, she left early.
The phrase removes the conjunction, the subject and the form of be. The price of that density is one thing: the phrase no longer has a subject and borrows one from the main clause.
Three shapes of the phrase
The shape depends on who performs the action and when it happened.
| Form | Meaning | Example |
|---|---|---|
| doing | a simultaneous active action or a cause | Feeling tired, she left early. |
| done | the subject undergoes the action | Written in 1890, the book still sells. |
| having done | the action finished earlier | Having finished, she went home. |
The passive of the perfect form is having been done: Having been warned, we took another road.
The phrase borrows its subject
This is the governing restriction of the whole topic. The phrase has no subject of its own, so it takes one from the main clause. If the subjects differ, the sentence falls apart.
Walking home, the rain started.
Walking home, I got caught in the rain.
There is one test: read the phrase and then the subject of the main clause. If they do not fit together, the phrase cannot be used.
What disappears along with the compression
The logical link goes out with the conjunction. A bare phrase does not show whether this is a cause, a time or a condition, and the reader has to infer it from the context.
Opening the door, she saw the letter.
Feeling tired, she left early.
If the link is not obvious, the conjunction is kept in front of the phrase. More on that at the next level.
The mistakes everyone makes
The first is using the phrase with different subjects.
Opening the door, the phone rang. → As I opened the door, the phone rang.
The second is taking an active form where the subject is passive.
Building in 1890, the bridge still stands. → Built in 1890, the bridge still stands.
The third is losing the comma after the phrase.
Feeling tired she left early. → Feeling tired, she left early.
All three are caught by one test. Read the phrase together with the subject of the main clause and ask whether that subject really performs the action.
Try it right now
Take two of your own sentences with because or when and rewrite them in English as phrases.
Then check each one: is the subject the same in both halves?