"If" is a common subordinating conjunction in English that introduces conditional clauses: parts of a sentence that state a condition on which another statement depends. In ordinary speech it links a protasis (the condition) and an apodosis (the result). Examples include "If it rains, we will stay inside" and hypothetical formulations such as "If I were you...".
Usage and types of conditional
English conditionals are often described in categories: real or possible conditions ("If she studies, she will pass"), counterfactual or unreal conditions using the subjunctive ("If I were king, I would..."), and past counterfactuals ("If they had left earlier, they would have arrived on time"). Modifiers and idioms create variations: "even if", "only if", and the biconditional expression "if and only if" (often abbreviated "iff" in mathematics) convey different logical relationships.
Grammar, origin, and notable distinctions
The word has roots in Old English (gif/if) and cognates in other Germanic languages. Grammatically it can begin direct or embedded conditional clauses and sometimes substitutes for "whether" in indirect questions. A key distinction is between natural-language conditionals and formal logical implication: conversational "if" often carries causes, expectations, or advice, while logical implication is a precise truth-functional relation used in mathematics and formal logic.
Computing and formal logic
In programming languages the keyword "if" controls conditional execution: code inside an "if" block runs only when a test evaluates true. In logic and mathematics, "if...then..." statements are used to express implications; authors and textbooks discuss how ordinary-language conditionals differ from the material implication studied in logic.
"If—" by Rudyard Kipling
"If—" is a didactic poem by Rudyard Kipling that appears in the "Brother Square Toes" chapter of the collection Rewards and Fairies. Presented as a set of paternal instructions, it celebrates qualities such as self-control, resilience, and moral steadiness. The poem is structured in a series of stanzas offering paired condition-and-reward lines and begins with the well-known injunction to "keep your head" when those around you lose theirs.
Its concise moral tone made the poem widely anthologized and memorized in the English-speaking world. In a 1995 BBC opinion poll it was voted Britain's favourite poem, a result often cited when discussing Kipling's popular reputation and the lasting cultural presence of the work. Critical responses vary—some praise its clarity and stoic ethic, others note its Victorian masculine ideals—but its influence on schooling and popular notions of practical virtue is undoubted. For further reading and historical context see resources and archives associated with Kipling and British literary surveys: further information.