After / Before –ing
Reducing time-relative clauses
Reducing time-related clauses
| FULL CLAUSE | |
|---|---|
Before, after, while, when, and since relate the timing to two events. These connectors take a clause as their complement. |
|
| INDEPENDENT CLAUSE | DEPENDENT CLAUSE |
Jack saw a skunk |
while he was walking. |
Jack stopped |
when he spotted it. (immediately after) |
Jack waited a short time |
before he continued on. (earlier) |
Jack still smelled the skunk |
after he passed that area. (later) |
Jack has been taking a new way home |
since he saw a skunk there. (from that time to now) |
| REDUCED CLAUSE | |
|---|---|
The clause may be reduced to a modifying clause if the subject of both clauses is the same. The verb in the modifying clause takes the form of a gerund (nonfinite clause). |
|
| INDEPENDENT CLAUSE | MODIFYING CLAUSE |
Jack saw a skunk |
while walking home. |
Jack stopped |
when spotting it |
Jack waited a while |
before continuing on. |
Jack could still smell the skunk |
after passing through the area. |
Jack has been taking a different way home |
since seeing a skunk there. |
spot (v.) – notice, identify, recognize
See Grammar Notes for grammar terms.
Reduced Clauses
Initial vs. Final Position
Initial vs. final clause position
| INITIAL | |
|---|---|
|
|
| MODIFYING CLAUSE | INDEPENDENT CLAUSE |
While walking home, |
Jack came across an animal. |
When spotting the animal, |
he stopped. |
Upon seeing a skunk, |
he turned around. |
Before continuing on, |
he waited a short time. |
After passing the area, |
he could till smell the skunk. |
Since seeing a skunk there, |
he has been taking a new way home. |
A | FINAL | |
|---|---|
|
|
| INDEPENDENT CLAUSE | MODIFYING CLAUSE |
Jack came across an animal |
while walking home. |
He stopped |
when spotting the animal. |
He stopped |
upon seeing a skunk. |
He waited a short time |
before continuing on. |
He could still smell the skunk |
after passing the area. |
He has been taking a different way home |
since seeing a skunk there. |
A came across – met my chance
upon – when
Reduced Clauses
Omitting When, While or Upon
Omitting an initial when or while clause
| WHEN / WHILE INCLUDED | |
|---|---|
A when or while modifying clause is placed directly before the subject noun (the person doing the action) in the main clause. |
|
| MODIFYING CLAUSE | SUBJECT NOUN |
When arriving home |
Jack greets his dog. |
While getting a drink of water |
Jack watches his dog. |
Upon bringing in his dog |
Jack wipes its paws. |
| WHEN / WHILE OMITTED | |
|---|---|
While or when can be omitted from a modifying clause. The same-time relationship will be understood from the context. |
|
| WHEN / WHILE OMITTED | SUBJECT NOUN |
Arriving home, |
Jack greets his dog.
|
Getting a drink of water, |
Jack watches his dog |
Bringing in his dog, |
Jack wipes its paws. |
*Yellow highlighting indicates example of incorrect usage.
(Upon means when.)
Related page Dependent / Independent Clause
Omitting a final when or while clause
| SUBJECT MODIFIER | |
|---|---|
A when, while or upon modifying clause placed after the main clause is still understood as a modifying the subject noun. |
|
| SUBJECT | MODIFYING CLAUSE |
Jack greets his dog |
when arriving home. |
Jack watches his dog |
while getting a drink of water. |
Jack wipes his feet |
upon entering the house. (modifies Jack) |
| OBJECT MODIFIER | |
|---|---|
Removing when, while or upon from the modifying may result in confusion. Which noun is being modified? |
|
| WHEN / WHILE OMITTED | SUBJ / OBJ MODIFIER? |
Jack greets his dog |
arriving home. (Jack or the dog?) |
Jack watches his dog |
*getting a drink of water. |
Jack wipes his feet |
entering the house. |
*Better placement: When coming home, Jack greets his dog. (Place modifier next to noun.)
Reduced Clauses
Omitting After
Expressing an earlier time in a reduced clause
| WHEN / WHILE INCLUDED | |
|---|---|
After is included in a reduced clause to express an earlier time frame of the activity in the clause. |
|
| MODIFYING CLAUSE | INDEPENDENT CLAUSE |
After being burglarized, |
Anne is very cautious. |
After closing the windows, |
Anne locked the front door. |
After setting the alarm, |
Anne locked the front door. |
| REDUCED | |
|---|---|
After is omitted from a modifying clause if the earlier time is expressed with the verb form — a past participle |
|
| AFTER OMITTED | INDEPENDENT CLAUSE |
Having been burglarized, |
Anne is very cautious. |
Having closed the windows, |
Anne locked the front door. |
Having set the alarm, |
Anne locked the front door.. |
burglarize (v.) – break in and steal from
cautious (adj.) – careful
Common Mistakes
Errors and Solutions
| ERROR | SOLUTION |
|---|---|
*Before taking a driving course, his father told him to be careful. |
Before the son took a driving course, his father told him to be careful. |
*Unfortunately, the ball hit Jack in the back of the head while running. |
Unfortunately, the ball hit Jack in the back of the head while Jack was running. (Restate the subject.) |
We stopped hearing the police siren. |
We stopped when hearing the police siren.
|
*Yellow highlighting indicates example of incorrect usage.
Grammar Notes
Traditional Grammar and Linguistic Description
"Adverbial Clauses" v. "Temporal Location Expressions"
| PAST GRAMMAR | CURRENT GRAMMAR |
|---|---|
In traditional grammar while, when, before, after, an since are conjunctions which join an adverb clause to an independent clause. The term adverbial clause is used because the clause adds time-related information about the verb and answers the question When? This added-on structure is called a dependent clause because it can not stand alone as a sentence. |
In current linguistic analysis – while, when, before, after, and since — are prepositions which take a clause as a complement: with a subject and a verb (while we were walking home) or with a gerund-participle (while walking home). Before and after additionally take a noun complement: (before me). The structure is called an adjunct because it is not required for completing the meaning of the sentence. |
Azar & Hagen call these adverbial clauses or "time clauses" with no mention of a term for the connector. It is not clear whether while, when, before, after, and since are adverbs or conjunctions. "A time clause begins with such words as when, before after, as soon as, until, and while and includes a subjects and a verb. The time clause can come either at the beginning of the sentence or in the second part of the sentence…" (UUEG 4-3, Adverb clauses 17-2; Reduction 18-1) |
Huddleston & Pullum (2009) have re-assigned a large number of items previously analyzed as adverbs after, as, as soon as, before, once, since while, and when to the class of prepositions. The preposition is the head of the prepositional phrase (PP) which can be complemented by a noun phrase or a clause with a subject and a verb, or a clause with a gerund-participle . (CaGEL 612-7) |
Quirk & Greenbaum (1989) place while, when, before, after, and since in the class of conjunction. They function as subordinators of adjunct clauses that express time-relationship. (CoGEL 8.53) |
Swan (2009) refers to while, when, before, after, and since as conjunctions. (Swan 30.1) |
Resources / Works cited
Practice 1
Same-time Events
Shorten the clause to a modifying clause if possible.
- Select the response from the list that best completes the sentence.
- Compare your response to the answer by clicking the "check" button.
Practice 2
Verb Forms in Modifying Clauses
Decide on the verb form.
- Select the response from the list that best completes the sentence.
- Compare your response to the answer by clicking the "check" button.