Grammar-Quizzes › Connectors › Connective Prepositions › While / When -ing
While / When -ing
Express time-related activities with reduced clauses
Reduce time-related clauses (temporal phrases)
| FINITE (FULL) CLAUSE | |
|---|---|
A temporal preposition such as before, after, when, while or since is added to the main clause to relate the timing of a second activity. The preposition can be complemented (completed) by a finite clause. The subject of the main clause may differ from the subject of the clause in the prepositional phrase. |
|
| MAIN CLAUSE | TEMPORAL PHRASE |
| SUBJECT'S ACTION IS MODIFIED | PREP + CLAUSE |
Jack saw a skunk |
while he was walking outside. while we were walking outside. |
Jack stopped |
when he spotted it. when his friend spotted it. |
Jack waited a short time |
before he continued on. before the skunk continued on. |
Jack still smelled the skunk |
after he passed the area. after the skunk left the area. |
Jack has been taking a new route home |
since he saw a skunk there. since the skunk sprayed the area. |
| OBJECT IS MODIFIED | PREP + CLAUSE |
Jack saw a skunk |
while it was digging up grass. |
| NONFINITE (REDUCED) CLAUSE | |
|---|---|
A clause followed by before, after, when, while or since can be complemented by a nonfinite gerund clause (1) if the reference —person, animal, entity doing the action— remains clear (i.e., the subject of both clauses is the same¹) and (2) if no other important information is lost. |
|
| MAIN CLAUSE | TEMPORAL PHRASE |
| SUBJECT'S ACTION IS MODIFIED | PREP + GERUND CLAUSE |
Jack saw a skunk |
while walking outside. |
Jack stopped |
when spotting it. It is understood that Jack spotted it. |
Jack waited a while |
before continuing on. It is understood that Jack waited. |
Jack could still smell the skunk |
after passing through the area. It is understood that Jack smelled it. |
Jack has been taking a new route home |
since seeing a skunk there. It is understood that Jack takes a new route. |
| OBJECT IS MODIFIED | PREP + GERUND CLAUSE |
Jack saw a skunk |
while digging up grass. |
spot (V) – notice, identify, recognize
since (P) – from a specific time until now; since may also mean "because".
¹unclear reference or misrelated modifier — See Misrelated Modifiers.
adjuncts — in grammar, words, phrases or clauses that add optional information about manner, degree, frequency, timing, and location of the activity or action. Adjuncts are mostly modifiers. (e.g., adverbs, some prep phrases, some modifiers) See Adjuncts.
complement (N) — a word, phrase or clause that completes the meaning of another element in the clause. In some cases, the complement is required in order to make sense. In other cases, the complement is not absolutely required but adds important modifying and identifying information For example, the verb see requires an object complement. John saw __(?)__. See Complement or Prepositional Complements.
temporal (Adj) – relating to the timing of an activity or action
Also see When/While (not reduced), Finite v. Nonfinite, Phrase v. Clause.
See Grammar Notes for terms. (These words are also called adverbials or conjunctions in some grammar systems.)
Word Categories: N – Noun; V – Verb; Aux – Auxiliary; Adj – Adjective; Adv – Adverb; P –Preposition; Det –Determiner. See Word Categories.
Phrasal Categories: NP – Noun Phrase; VP – Verb Phrase; AdjP – Adjective Phrase; AdvP – Adverb Phrase; PP – Prepositional Phrase; DP – Determinative Phrase.
Clausal Categories: Cls – clause; F – finite clause; NF – nonfinite clause: Ger – gerund; Inf – infinitive; PPart – past participle.
Word Functions: Subj – subject; Pred – predicate/predicator; Comp – complement: elements required by an expression to complete its meaning (DO – direct object; IO – indirect object); Adjunct – adjunct: elements not required by an expression to complete its meaning (Subord – subordinator; Coord – coordinator); Supl – supplement: a clause or phrase added onto a clause that is not closely related to the central thought or structure of the main clause.
Reduced Clauses
Initial vs. Final Position
Positioning the phrase before vs after the main clause
| INITIAL | |
|---|---|
|
|
| TEMPORAL PHRASE | MAIN CLAUSE |
While walking home, (same) |
Jack came across an animal. |
When spotting the animal, (1st) |
he stopped. (2nd) |
Upon seeing a skunk, (1st) |
he turned around. (2nd) |
Before continuing on, (2nd) |
he waited a short time. (1st) |
After passing the area, |
he could till smell the skunk. |
Since seeing a skunk there, |
he has been taking a new way home. |
The prepositional phrase can be moved in front of the main clause for emphasis. A comma is placed after it.| FINAL | |
|---|---|
|
|
| MAIN CLAUSE | TEMPORAL PHRASE |
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. |
came across – met my chance
upon – when
Reduced Clauses
Omitting When, While or Upon
Omitting when, while and upon
| WHEN / WHILE INCLUDED | |
|---|---|
A prepositional phrase with when or while can be placed directly before the subject noun (the person doing the action) in the main clause. The temporal (time-related) phrase is understood as a modifier to the closest noun in the main clause—the subject. |
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| MODIFIER | MAIN CLAUSE |
| TIME-RELATED REDUCED CLS | SUBJECT IS MODIFIED |
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 only if it is clear who or what the modifying phrase refers to. Position the nonfinite clause next to the noun it modifies. The same-time relationship will be understood from the context. |
|
| MODIFIER | MAIN CLAUSE |
| GERUND CLS | SUBJECT IS MODIFIED |
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 Clause
| SUBJECT MODIFIER | |
|---|---|
A when, while or upon modifying phrase placed after the main clause is still understood as modifying the subject noun. |
|
| MAIN CLAUSE | MODIFIER TO SUBJ |
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. |
| OBJECT MODIFIER | |
|---|---|
Removing when, while or upon from the modifying phrase may result in confusion. It is unclear which noun the modifier refers to! |
|
| MAIN CLAUSE | MODIFIER TO SUBJ or OBJ? |
Jack greets his dog |
*arriving home. |
Jack watches his dog |
getting a drink of water. |
Jack wipes his feet |
entering the house. |
*Better placement: Arriving home, Jack greets his dog. / Jack, arriving home, greets his dog. Place the modifier directly before or after the noun to help clarify the reference.
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 than that of the main clause. No change to the (nonfinite) verb form is required. |
|
| MODIFIER | MAIN CLAUSE |
| SAME-TIME | SUBJECT IS MODIFIED |
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 can be omitted from a modifying clause. However, the earlier time is then expressed in the form of the verb—a past participle. Past Nonfinite. |
|
| MODIFIER | MAIN CLAUSE |
| EARLIER | SUBJECT IS MODIFIED |
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 and Solution
| ERROR |
|---|
*Before taking a driving course, his father told his son to be careful. Who is taking the driving course? |
*Unfortunately, the ball hit Jack in the back of the head while running. Who was running – the ball or Jack? |
We stopped hearing the police siren. (Unclear – this means we were no longer hearing the sound.) |
| SOLUTION |
|---|
Before the son took a driving course, his father told him to be careful. Do not use a reduced clause if it is not clear who is doing the action in it. |
Unfortunately, the ball hit Jack in the back of the head while Jack was running. (Restate the subject.) Unfortunately, Jack was hit in the back of the head while [he was] running. (Reword the sentence with Jack as the subject of the main clause.) |
We stopped when we heard the police siren. We stopped being able to hear the police siren. (no longer able) |
*Yellow highlighting indicates example of incorrect usage.
Grammar Notes (Advanced)
Traditional and Linguistic Descriptions
| TRADITIONAL GRAMMAR |
|---|
Adverbial Clauses 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.
Swan (2009) refers to while, when, before, after, and since as conjunctions. (30.1) |
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…" (4-3, Adverb clauses 17-2; Reduction 18-1) |
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. (8.53) |
| LINGUISTIC DESCRIPTION |
|---|
Temporal Location Expressions In current linguistic analysis—while, when, before, after, and since —have been re-classified into the category of preposition. Each of these temporal expressions takes a finite clause or nonfinite clause as its complement.
(Note that a Preposition is not limited to a noun complement. In fact, it may take a number of structures as its complement. Prep Complements) |
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 Preposition. 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. (612-7) |
The structure is called an adjunct because it is not required by the verb to complete the sentence. It adds additional information.
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Works Cited
- Azar, Betty Schrampfer, and Stacy A. Hagen. Understanding and Using English Grammar. 4th ed., Pearson Education, 2009.
- Huddleston, Rodney D., and Geoffrey K. Pullum. The Cambridge Grammar of the English Language. Cambridge UP, 2002.
- Swan, Michael. Practical English Usage. 3rd ed., Oxford UP, 2005.
- Quirk, Randolph and Sidney Greenbaum. A Comprehensive Grammar of the English Language. 7th ed., Longman Group, 1989.
Practice 1
Same-time Events
If possible, shorten the clause to a modifying clause.
- Select the response from the list that best completes the sentence.
- Compare your response to the feedback by clicking the "check" or "check 1-10" button.
Practice 2
Verb Forms in Modifying Clauses
Decide on the verb form that should be used in the reduced clause.
- Select the response from the list that best completes the sentence.
- Compare your response to the feedback by clicking the "check" or "check 11-16" button.