Grammar-Quizzes Connectors › Connective Prepositions

Connective Prepositions (adjuncts, conjunctions)

Relate additional information to a clause

X structure diagram
We walk because we like walking.
‹ diagram ›
► How is a preposition a connective? ▼ Explanation of term

A prepositional phrase may be:

  1. a complement — which adds modifying (necessary) information to complete the meaning of the clause — it modifies a noun or a verb with information such as timing, location, or manner. A prepositional phrase is typically short and may include another prepositional phrase. The preposition is usually followed by a noun phrase : We began in the morning.  Our walk in the morning on the beach is refreshing.  The preposition may include the noun: We exercise indoors. See Preposition Uses.
  2. an adjunct — which adds modifying (extra, unnecessary) information before or after the clause — it modifies the clause with information such as reason, purpose, condition, comparison, or relative timing. A connective prepositional phrase is longer. The preposition is followed by a finite clause (a full clause), a nonfinite clause (a gerund clause), a noun phrase or a prepositional phraseWe began walking because we needed exercise. We began walking because of our health. We began walking after eating. We began walking after breakfast.  (Note that the main clause can stand on its own without the adjunct prepositional phrase.)

The head preposition of a phrase:

  • is the primary word of the prepositional phrase.  It is called a head because of (1) its beginning (initial) position in the phrase → We walk [because we like fresh air] or (2) its role (meaning) in the phrase → We walk [because (reason) we like fresh air.  In the case of a double preposition, it is the first preposition that is the head.  We walk inside of the park.  We can't get out of the house early enough.
  • functions as the connector between the main clause and the phrase. It also relates the information in the phrase to the central idea of the main clause. 
  • relates a phrase expressing a meaning of: reason (because, since, as), concession (though, despite), purpose (in order, so that), time-relative (after, before, when, while, until), condition (if , unless), an expression (in a flash), comparison (than, as, of, from or to) and more.
  • takes form as:
    • a preposition—before, after, while, because, though, until, as, than, if , and so on—may take a complement of a noun phrase, a gerund, an infinitive, a full clause or another structure, depending on the meaning of the preposition: before midnight (N), before the midnight hour (NP), before leaving home (Ger), He prefers to leave early rather than to leave late (Infin), before we left home (clause). 
    • a comparative prepositionas, than, of, from or to—followed by a full or reduced clause. He walks as fast as I walk. He walks faster than I do. He walks the fastest of us all. He walks a different route from the one we walk. His route is similar to our route.) 
    • a conditional prepositionif or unless— followed by a clause expressing a condition. We walk [if we have time].

How does a connective preposition differ from a coordinator (and, but, or) or subordinator (that, if, whether)?

  • the head preposition is part of (holds meaning in) the phrase that it adds. It cannot be omitted without a loss of meaning → She is tired [because she walks.] 
    • a subordinator (that) is not part of the clause that it joins, rather it is a marker before the subordinated clause. That can often be omitted. → She says [that] she likes walking. If and whether are not omitted. (I don't know [whether] she actually does.)
    • a coordinator (and +, but–, or+/-) is not a part of either clause that it joins and has little (minimal) meaning. It can usually be omitted. → (She likes to walk; he does too. She wears running shoes; he wears track shoes.) The relationship of the clauses can be understood from context. Or is not omitted. (Do your best [or] go home.)
  • the meaning expressed by the preposition can usually be modified by an adverb such as [1] a focusing adverb (He walks only because his health requires it.) or [2] a degree adverb (He walks partly for his health. He walks right in the middle of the path.)

Also see other clausal headswho, when, where, why—(interrogative pronouns) that occur in embedded wh-questions. Similar to other phrasal heads, the head of the clause is the connective, and it carries meaning as part of the clause. She told me who is coming. She told me whom she invited__.  (An object pronoun is moved to the beginning (head) of the clause.)


The Cambridge Grammar of the English Language (2002) included some major changes to the category of Preposition. At first look, the recategorization of several adverbs and conjunctions as prepositions upsets what we thought we knew about prepositions. However, on closer examination, the recategorization makes a lot of sense. Linguistic research has produced (1) a description of English that is more logical and concise than the traditional Latin-based grammar we were using; (2) terms that can be applied globally to all languages (i.e., a word categorized [defined by properties] as Preposition in English will function in the same way as words called Preposition in other languages.)


  1. One result is that the category Preposition has been widened to include words such as—before after, while, because, though, if, than, and as. Linguistic analysis determined that these words functioned more similarly to prepositions than to conjunctions, adverbs or other categories in which they had previously been placed.
  2. Another result is that prepositional complements (structures that can follow prepositions) have been widened. A preposition is not limited to a noun as its "object". The complement of a preposition could be a word, phrase or clause—at home (N), in the house (NP), out of the house (PP), in stead of later (Adv), after leaving (gerund), because we left (clause). See Prepositions–Range of Complements.



This Connective is also called an adverbial preposition. The structure is called an adjunct prepositional phrase (linguistic description) or an adverbial clause (traditional term). See Connector Overview: Grammar Notes for grammar source details.


Also called: Adjunct Prepositions, Adverbial Prepositions, Subordinating Conjunctions, or Adverbials.

Different from: Prepositional Phrase (complement) — the phrase completes the meaning expressed by the subject and predicate


Connective Prepositions (a.k.a. adjunct preps, adverbial preps, conjunctions)

Summary of Practices



Preposition Overview

Preposition Uses: recognize how prepositions function in clauses

Beginning–Advanced ESL, Native Speakers

Canyon explorer

Under the canyon floor is a stream of water.

Jack is in the middle. (location)

Jack climbed down. (location)

Jack explores with enthusiasm. (manner)

Jack gets up early in order to go climbing. (purpose)


Because: express a causal relationship

Intermediate– Advanced ESL, Native Speaker

Girls School

She married at the age of thirteen because she had no other options.

She had no other options. Consequently, she married at the age  of thirteen.

Illiteracy results from a poor childhood education.

A poor childhood education results in illiteracy.

Because of vs. Despite: indicate a causal or non-causal relationship (adverbial prepositions)

Beginning–Advanced ESL, Native Speaker


Because of the gas explosion / an  exploding gas line, several homes burned down. (reason)

Due to old age, the pipe cracked. (reason)

On account of the accident, all pipes are being inspected. (reason)

New regulations were enacted owing to the lessons learned. (reason)

Despite their quick arrival, the firemen could do nothing. (contrary reasoning)

The fire burned the neighborhood in spite of the effort of fire fighters. (contrary reasoning)

Because of vs. By: indicate cause vs. method

Advanced ESL, Native Speaker

Demonstrations in Egypt

Demonstrators protested because of high unemployment. reason

Demonstrators protested by marching in the street. means

Progress was made because of the opposition leaders. reason

Progress was made by the opposition leaders.  agent

Because Reduced Clause: express cause in a shortened clause

Beginning–Advanced ESL, Native Speaker

working hard

Because Tom worked so hard, he earned a good salary. (same time)

Working so hard, Tom earned a good salary. (same time)

Because Tom had been working so hard, he needed a vacation.

Having worked so hard (earlier time), Tom needed a vacation.

Because vs. Though: express reasoning—cause-effect or noncause-effect

Intermediate– Advanced ESL, Native Speaker

Snow travel

He wore his winter pants because it was snowing. Schools were closed because of the snow.

It was snowing.  For this reason, the schools were closed.

He was biking in his shorts though it was snowing.

The schools were open in spite of the cold temperature.

It was snowing.  Nevertheless, the schools were open.

But vs. Though: express defeat versus challenge

Beginning–Advanced ESL, Native Speaker

job seeker

Brian planned on attending a job fair, but the line was very long.   (It discouraged him..)

Brian planned on attending a job fair though the line was very long.   (He stood in it anyway.)

Cause-Effect Overview: express cause and effect relationship

Beginning–Advanced ESL, Native Speaker

Newton's Cradle

His computer froze, so he hit it.

He hit it so hard that he damaged the keyboard.

He took it to a repair center because it needed a new keyboard.

He paid a lot to have it fixed.  As a consequence, he never hit his computer again.

After Before When: relate the timing of two activities

Intermediate ESL, Native Speakers

Movie watchers

We watch a movie after he arrives. (present habitual)

We will watch a movie until he arrives. (future) 

We will watch a movie as soon as he arrives.

We will be making popcorn while he is driving here.

We will have had a good time by the time the evening ends.

Time-Relative Events: relate the timing of two connected events

Intermediate–Advanced ESL


After I make tea, we will watch a movie on TV .

I will make tea. Afterward, we'll watch a movie on TV

I will make some tea before we watch a movie on TV.

When vs. While: relate same-time (synchronous) activities

Intermediate ESL, Native Speaker

Talking on phone and looking at newborn

When you called, he picked up his phone. (interruption)

While he was talking on the phone, the baby slept. (same-time)


When I call, the doctor comes. (about same time)

When the doctor comes in, I ask questions.  (immediately after)

By the time: view relative progress or completion (hypothetical)

Intermediate– Advanced ESL, Native Speaker


By the time I leave work, the sun will be setting. (ongoing)

By the time I leave work, the sun will have set. (completed)

If vs. When: express a singular condition vs. a recurring action

Intermediate-Advanced ESL, Native Speakers

cloth shopping bag

If he goes shopping today, he'll get some light bulbs.

If/When he goes shopping, he takes a bag.

If he went shopping yesterday, he got some light bulbs. 

If/When he went shopping, he took the car. 

Prep Phrases with Gerunds: Relate a second activity to the first activity

Intermediate–Advanced. ESL

watching tv

Jason read the manual before beginning the installation.

You can't turn it on without plugging it in.

Jane got it working by using a different cable.

Jason was talking about watching an action movie.

While vs. When -ing: express time-relative activities with reduced clauses

Intermediate– Advanced ESL, Native Speaker


While John was walking home, he came across a skunk.

While walking home, John came across a skunk.  

Walking home, John came across a skunk. 

Walking home from school, *a skunk sprayed John. 

So that vs. So: express purpose vs. result

Intermediate– Advanced ESL, Native Speaker

Meteor Shower

We stayed up all night so that we could watch a meteor storm. (prep + content clause)

We stayed up late, so we were able to see the meteor storm pass. (connective adverb + content clause).

We stay up so late that we were able to see the meteor storm pass. (adverb expression + content clause)

"In order" + Infinitive: state purpose

Beginning–Advanced ESL

Doctor operating on a patient/victim

The doctor operated in order to save his patient's life.

The doctor operated so that they could save his patient's life..

Rather than: comparative preferences

Intermediate– Advanced ESL, Native Speaker

walk to work

We would rather walk to work than drive. (coordinator: X and not Y)

We walk to work rather than drive. (X and not Y)

We walk to work rather than get caught in traffic.  (subordinator: choosing X to avoid Y)

If vs. Unless: express a specific condition for an outcome   (Conditional Summary)

Intermediate-Advanced ESL, Native Speakers


If you cook your turkey like this, you will have a tender turkey.

Only if you cook your turkey like this, will you have a delicious dinner.

Unless you cook your turkey like this, you will have a tough turkey.

Cook your turkey like this. Otherwise, you will have a tough turkey.

Omitting if: give advice in hypothetical situations

Intermediate-Advanced ESL, Native Speakers


If I were/was you, I wouldn't get involved.

Were I you, I wouldn't get involved.

Had I known, I would have said something.

Should you see him again, call me immediately.

If vs. In Case: state a conditioned vs. a precautionary action

Intermediate-Advanced ESL, Native Speakers


Keep some extra batteries and bottled water In case there is an earthquake.

Get away from falling objects if there is an earthquake.

Conditional Summary

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If you speak English, you will qualify for the job. (You will likely apply for the job.) pres. real

If you spoke English, you qualified for the job. (You likely applied for the job.) past. real

If you spoke English, you would qualify for the job (You don't, so you won't apply for the job).  pres. unreal

If you had spoken English, you would have qualified for the job . (You didn't, so you didn't apply for the job). past. unreal

likely (Adv) – probably
qualify (V) – have the required skills, knowledge or credentials.