Conditional Sentences

Glossary of Grammatical and Rhetorical Terms

conditional sentence
"If wishes were horses, beggars would ride." This English proverb is an example of a conditional sentence. (Colin Anderson/Getty Images)

In English grammar, a conditional sentence is a type of sentence that expresses one situation (the condition, antecedent, or protasis in a dependent clause) as a condition for the occurrence of another situation (the result, consequent, or apodosis in the main clause). Put simply, the basic structure underlying most conditional sentences can be expressed as, "If this, then that." Also called a conditional construction or a conditional. In the field of logic, a conditional sentence is sometimes referred to as an implication.

A conditional sentence contains a conditional clause, which is a type of adverbial clause usually (but not always) introduced by the subordinating conjunction if, as in, "If I pass this course, I will graduate on time." The main clause in a conditional sentence often includes the modal will, would, can, or could.

A subjunctive conditional is a conditional sentence in the subjunctive mood, such as, "If he were to show up here right now, I'd tell him the truth."

Examples and Observations

In each of the following examples, the italicized word group is a conditional clause. The sentence as a whole is a conditional sentence.

  • "If I ruled the world,
    Every man would be as free as a bird,
    Every voice would be a voice to be heard,
    Take my word, we would treasure each day that occurred."
    (Leslie Bricusse and Cyril Ornadel, "If I Ruled the World." Pickwick, 1963)
  • "If I ruled the world, was king on the throne,
    I'd make peace in every culture, build the homeless a home."
    (Nasir Jones et al., "If I Ruled the World (Imagine That)," 1995)
  • "Now, if I had been that young woman, I would have planted my feet, looked those men straight in the eye, and dared them to try to put me on board a ship when I didn't want to go, but times were different then."
    (Jennifer Chiaverini, The Quilter's Apprentice, 1999)
  • "Even if she were to confide in them all her suspicions, even if she were to tell them about the pills, even if she were to lead them to her locker at the Greyhound Bus Terminal and actually present them with her bloodied dress and the stacks of hundred-dollar bills, she would be regarded with skepticism and outright disbelief."
    (Joy Fielding, See Jane Run. William Morrow, 1991)
  • "All this can be a dreadfully boring business, unless you think you have a future."
    (Bernard Malamud, "The German Refugee," 1964)
  • Conditional Clauses That Are Not Introduced by a Conjunction
    - "It is possible to construct conditional clauses that do not begin with if or unless. The commonest way of doing this is to begin the clause with one of these words: were, should, had. For example: Were I to own a new BMW car, another ten microcomputers would be at my command, so their advertisements claim.
    Should you succeed in becoming a planner, you would be helping to create these parameters.
    Had I ignored my fitness, I could never have played international cricket for twenty years." (John Seely, Oxford A-Z of Grammar and Punctuation, rev. 2nd ed. Oxford University Press, 2013)
    - "Were I to take a turn into the country, the trees would present a leafless, wintry appearance."
    (Thomas Paine, winter 1792)
    - "Let Domingo be my heir should I fail to return, I said to the House that surrounded me."
    (Jane Lindskold, Child of a Rainless Year. Tor Books, 2005)
    - "Yet this strangest of all things that ever came to earth from outer space must have fallen while I was sitting there, visible to me had I only looked up as it passed."
    (H.G. Wells, The War of the Worlds, 1897)
  • Using the Past Perfect in Conditionals
    "If the situations are set in the past, the past perfect is used in the conditional clause and a past perfect modal, usually would have, in the main clause. - If we had been there yesterday, we would have seen them. (But we were not there yesterday.)
    - If he had been given a good mark, he would have told me. (But it seems that he was not given a good mark.) "If the auxiliary in the conditional clause is were, had, or should, we can omit if and front the auxiliary: - Were she here now, there would be no problem.
    - Had we stayed at home, we would have met them.
    - Should you see him, give him my best wishes." (Sidney Greenbaum and Gerald Nelson, An Introduction to English Grammar, 2nd ed. Pearson, 2002)
  • Direct and Indirect Conditions
    "Conditional clauses generally express a direct condition, indicating that the truth of the host clause (or apodosis) is dependent on the fulfillment of the condition in the conditional clause (or protasis). However, some conditional clauses may express an indirect condition that is related to the speech act: [18]  And if I remember rightly you had jaundice didn't you ('if I remember rightly it would be true to say')
    [19]  I mean if I told you honestly things can be really interesting [...]
    [20]  [. . .] I did need to have a need to say <,> that I was doing something because uhm <,> otherwise I wouldn't be anybody if you see what I mean "Direct conditions may be either open (or real) or hypothetical (or closed or unreal). Open conditions leave completely open whether the condition will be fulfilled: [21] You're going to have huge trouble <,> if you've infected me. In [21] the speaker does not give any indication whether he or she believes that the condition--the infection by the person addressed--has been fulfilled."
    (Sidney Greenbaum, Oxford English Grammar. Oxford University Press, 1996)
  • Material Conditionals in Logic
    "A material conditional expresses another type of connection, neither causal nor logical yet similar to other types of conditionals in that it cannot be true if it has a false consequent and a true antecedent. An example of a material conditional is If humans live on Jupiter, then my great-grandmother was an astronaut. Although no natural link connects the antecedent and consequent in this conditional, its meaning is clear. The point of this sentence, and others like it in English, is to emphasize that the antecedent is false. It is a way of expressing 'No way is there human life on Jupiter.'
    "Although material conditionals are often just humorous ways of stating that something is false, we can draw from them a logically useful principle about interpreting sentential connectives. In a material conditional, the 'if... then...' that connects the component sentences is a truth-functional connective. This means that the truth of the conditional sentence is determined completely by (is a function of) the truth of its component sentences. The only circumstance under which a material is false is when it has a true antecedent and a false consequent. That is why the compound sentence 'If there's human life on Jupiter then my great-grandmother was an astronaut' can be used to state the falsity of 'there is human life on Jupiter.' The consequent of the conditional ('my great-grandmother was an astronaut') is obviously false. Yet the sentence as a whole is understood as true. But if the antecedent were true, then the conditional would be false, for it would have a true antecedent and a false consequent. Thus, a material conditional of the form If (antecedent), then (consequent) is true unless the antecedent is true and the consequent is false." (Merrilee H. Salmon, Introduction to Logic and Critical Thinking, 6th ed. Wadsworth, Cengage, 2013) 
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Your Citation
Nordquist, Richard. "Conditional Sentences." ThoughtCo, Aug. 26, 2020, Nordquist, Richard. (2020, August 26). Conditional Sentences. Retrieved from Nordquist, Richard. "Conditional Sentences." ThoughtCo. (accessed March 23, 2023).