Adverbs of Purpose


Adverbs of purpose (sometimes called adverbs of reason) tell us why something happens or is the case. They can modify verbs, adjectives, or adverbs.

Types of Adverbs of Purpose

Adverbs of purpose are generally made up of conjunctive adverbs, prepositional phrases, infinitive phrases, or adverbial clauses.

Conjunctive adverbs of purpose

We often use conjunctive adverbs to indicate a relationship of reason or purpose between two independent clauses. Some common conjunctive adverbs of purpose are thus, therefore, consequently, hence, and as a result.
When we join two independent clauses with a conjunctive adverb, they are traditionally separated with a semicolon.
It is also acceptable to use a period and keep them as two discrete sentences. The conjunctive adverb still usually appears at the beginning of the second sentence, but it can also appear before or after the word it is modifying.
For example:
  • “Jen hadn’t enjoyed the play; as a result, she didn’t recommend it.”
  • “We’ve never seen such high numbers. We must therefore conclude that the results are not normal.”
  • “I’ve had some bad experiences with business partners in the past. Consequently, I am a little nervous about entering into this deal.”
  • “The market here has been shrinking every year. We have thus decided to close our branch in this country.”
  • “There has been some talk of the company going bankrupt in the near future; she is consequently looking for a new job.”
  • “I broke my leg last month; hence, I was unable to work for several weeks.”

Non-conjunctive adverbs of purpose

It is also possible to use many of the adverbs above in a non-conjunctive manner, especially when modifying an adjective that derives purpose or reason from a previous part of the sentence. For example:
  • “The clothing is handcrafted and hence expensive.”
  • “I’ve grown fond of our time together and am thus sad to see it end.”
  • “The markets proved to be volatile and therefore unreliable.”

Adverbial phrases of purpose

A variety of phrases are often used to indicate purpose or reason. The most common of these are prepositional phrases and infinitive phrases.

Prepositional phrases

It is very common to use prepositional phrases adverbially, and in some cases they can be used to indicate purpose. These prepositional phrases usually occur at the end of the clause, appearing after the verb or adjective they are describing, but they can also appear at the beginning of a clause or sentence, in which case they are set apart by a comma.
The most common prepositional phrase of purpose uses the compound preposition because of, as in:
  • “I am feeling tired because of this cold.”
  • Because of my operation, I had to cancel my flight.”
Some other common prepositions that can create prepositional phrases of purpose are for, given, owing to, and due to*. For example:
  • “Every year, we honor the soldiers who sacrificed their lives for their country.”
  • Given the huge amount of public interest, they are extending the program for another three months.”
  • “Our game was delayed due to rain.”*
  • “He had to leave early owing to an emergency at the hospital.”
(*Note: Some traditional grammarians insist that due should never be used as a preposition, and that it should instead only be used as an adjective. However, there is no logical reason that it can’t function as part of the compound preposition due to, and it is very often used this way in both formal and informal speech and writing.)

Infinitive phrases

An infinitive is the most basic form of a verb. It is “unmarked” (which means that it is not conjugated for tense or person), and it is preceded by the particle to. Any predicative information that follows an infinitive verb creates what’s known as an infinitive phrase.
Infinitives and infinitive phrases can serve as nouns, adjectives, or adverbs. Infinitives always indicate purpose when they function as adverbs, and for that reason they are sometimes known as infinitives of purpose. For example:
  • “I started running to improve my health.”
  • “I went to the store to buy some milk.”
We can also use the phrases in order and so as to add formal emphasis to an infinitive of purpose, as in:
  • “We must leave now in order to catch our train.”
  • “He’s been working quietly so as not to disturb his roommates.”

Lone infinitives of purpose

We can also use infinitives in this way as isolated responses to questions asking why something is done or is the case. For example:
  • Speaker A: “Why are you going to New York?”
  • Speaker B: “To see the Empire State Building.”
  • Speaker A: “Why did you turn on the TV?”
  • Speaker B: “To watch the news.”
These responses are known as elliptical sentences, meaning that part of the sentence has been omitted because it is implied. In the last example, the implied section is “I turned on the TV because I wanted….” As this element is implicitly understood, we often leave it out entirely and simply use the infinitive on its own.

Adverbial clauses of purpose

We can also use the subordinating conjunctions as, because, since*, so (that), in order that, for fear that, hence, or (less commonly) lest** to create adverbial clauses that indicate reason or purpose. For example:
  • “I am exhausted because I was working all night.”
  • As it’s raining, we probably shouldn’t play in the park today.”
  • “I’m going to Johnny’s house later since all my homework is finished.”*
  • “He left the house so (that) he could be alone.”
  • “I take my kids hiking in the mountains each summer in order that they learn to appreciate nature's beauty.”
  • For fear that his son may get hurt, Dan never lets him play any contact sports.”
  • “I should explain myself to him, lest he thinks I am being ungrateful.”**
(*Be careful with the subordinating conjunction since, because it is also used with adverbial clauses of time, as we saw above.)
(**The subordinating conjunction lest is not commonly used today, as it sounds old-fashioned and overly formal in modern English.)

1. Which of the following cannot be used to form adverbs of purpose?

2. Which of the following sentences does not use an adverb of purpose?

3. Which of the following prepositions can be used to form a prepositional phrase of purpose?

4. Where can adverbial clauses of purpose appear in a sentence?

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