Conditional Clause in Grammar

Glossary of Grammatical and Rhetorical Terms

Blackberry jam reaching boiling point
"The equilibrium between liquid and vapor is upset if the temperature is increased." is an example of a conditional clause.

Sharon Vos-Arnold / Getty Images

In English grammar, a conditional clause is a type of adverbial clause that states a hypothesis or condition, real (factual) or imagined (counterfactual). A sentence containing one or more conditional clauses and a main clause—which expresses the result of the condition—is called a conditional sentence or conditional construction.

A conditional clause is most often introduced by the subordinating conjunction if; other conditional subordinators include unless, even if, provided that, on [the] condition that, as long as and in the case of. Note that unless functions as a negative subordinator.

Conditional clauses tend to come at the beginning of complex sentences— sentences containing an independent clause and one or more dependent clauses—but, like other adverbial clauses, may also come at the end. 

What Are Conditions?

But what exactly is a condition? Ronald Carter and Michael McCarthy define this in their book Cambridge Grammar of English. "Conditions deal with imagined situations: some are possible, some are unlikely, some are impossible. The speaker/writer imagines that something can or cannot happen or have happened, and then compares that situation with possible consequences or outcomes, or offers further logical conclusions about the situation," (Carter and McCarthy 2006).

Placing Conditional Clauses

As mentioned, a conditional clause may be put either at the beginning or end of a sentence. Author Kenneth A. Adams explains how best to decide where to place this kind of clause: "Conditional clauses have traditionally been placed at the beginning of a sentence, but you should feel free to place a conditional clause elsewhere if doing so would make the provision easier to read.

The longer the conditional clause, the more likely it is that the provision would be more readable with the matrix clause rather than the conditional clause at the front of the sentence. If both the conditional clause and the matrix clause contain more than one element, you would likely be better off expressing them as two sentences," (Adams 2013).

Types of Conditional Clauses

There are six main types of conditional sentences based on likelihood and tense: general rule/law of nature, open future condition, unlikely future condition, impossible future condition, impossible past condition, and unknown past condition. See below for definitions and examples of these, provided by John Seely in Grammar for Teachers.

  • General rule: This event or action is a law of nature, it always happens. Example: "The equilibrium between liquid and vapor is upset if the temperature is increased."
  • Open future condition: This event or action may or may not happen. Example: "If you start thinking about this game, it will drive you crazy."
  • Unlikely future condition: This event or action probably won't happen. Example: "But if you really wanted to be on Malibu Beach, you'd be there."
  • Impossible future condition: This event or action could never happen. Example: "If I were you, I would go to the conference center itself and ask to see someone in security."
  • Impossible past condition: This past event or action did not happen. Example: "I would have resigned if they had made the decision themselves."
  • Unknown past condition: The conditions of this past event or action are unknown; it might have happened and it might not have. Example: "If he had been working for three days and three nights then it was in the suit he was wearing now," (Seely 2007).

Examples and Observations

Continue practicing using and identifying conditional clauses to build your reading and writing skills. Use these quotes from literature—and notice how the conditional clauses are italicized—to get started.

  • " If we had no winter, the spring would not be so pleasant; if we did not sometimes taste of adversity, prosperity would not be so welcome," (Bradstreet 1672).
  • "Romans park their cars the way I would park if I had just spilled a beaker of hydrochloric acid on my lap," (Bryson 1992).
  • "Even if it snows, even if there is a tornado, nothing will put off this expedition," (Powers 1950).
  • "After that first taste of the sandal in the dining room, I foolishly believed I would be safe as long as I stayed away from the table," (Kress 2007).
  • "If you can keep your head when all about you/Are losing theirs and blaming it on you,/If you can trust yourself when all men doubt you,/But make allowance for their doubting too;/If you can wait and not be tired by waiting,/Or being lied about, don't deal in lies,/Or being hated, don't give way to hating,/And yet don't look too good, nor talk too wise...,"(Kipling 1910).

Sources

  • Adams, Kenneth A. A Manual of Style for Contract Drafting. 3rd ed. American Bar Association, 2013.
  • Bradstreet, Anne. "Meditations Divine and Moral." 1672.
  • Bryson, Bill. Neither Here Nor There: Travels in Europe. William Morrow, 1992.
  • Carter, Ronald, and Michael McCarthy. Cambridge Grammar of English. Cambridge University Press, 2006.
  • Kipling, Rudyard. "If". Rewards and Fairies. Doubleday, 1910.
  • Kress, Adrienne. Alex and the Ironic Gentleman. Weinstein Books, 2007.
  • Powers, J.F. "Death of a Favorite". The New Yorker. 23 June 1950.
  • Seely, John. Grammar for Teachers. Oxpecker, 2007.