could
verb (intransitive)
UK/kʊd/US/kʊd/
A modal verb used to indicate possibility, past ability, or to make polite requests and offers.
Example Sentences
She could swim across the lake when she was younger.
It could rain later, so take an umbrella just in case.
Could you please pass the salt?
He could not attend the meeting due to prior commitments.
If we leave now, we could arrive by noon.
They could see the mountains clearly on a clear day.
I could help you with your homework if you need assistance.
Given the current circumstances, we could face delays in the project timeline, which might require us to adjust our plans accordingly.
Thesaurus
Synonyms
Antonyms
How to Use
Expresses past or conditional ability, polite requests, or possibilities.Used as a modal verb, “could” conveys abilities or circumstances in the past—“I could swim well when I was younger”—and also frames possibilities or hypothetical scenarios—“It could rain tomorrow.” In present or future contexts, it often shows something is possible but not certain—“We could go to the movies,” offering a suggestion. Politeness is another major function: “Could you pass the salt?” sounds softer than “Can you pass the salt?” Grammatically, it pairs with a base verb (“could see,” “could do,” “could help”) to modify meaning. Also, “could have + past participle” signals a missed or unrealized possibility—“We could have visited the museum, but it was closed.” When deciding whether to use “could,” ask if you’re describing a past ability, a potential outcome, or a polite request. That ensures clarity about the timeframe or degree of certainty you intend.
Alternatives
If you want variants, “might” also shows possibility with slightly more uncertainty—“We might see a movie.” “Would” can suggest willingness or a conditional future—“Would you open the door?” “Can” expresses a more direct or immediate ability or opportunity—“Can you pass the salt?” “Should” shifts to advice—“We should leave soon if we don’t want to be late.” Meanwhile, “may” or “might” lean toward polite or formal possibilities. “Could” remains versatile for gentle suggestions, past abilities, or hypothetical scenarios, so pick the one that best aligns with the time frame or tone you wish to convey—whether it’s politeness, speculation, or a missed chance.
Writing
In written form, “could” deftly introduces speculation, polite requests, or discussion of past capabilities. In academic or analytic contexts, you might say, “One could argue that this data supports the hypothesis,” to keep the tone measured and open-ended. In narratives or essays, it can depict alternative outcomes—“He could have taken the shortcut but decided against it”—or highlight a character’s potential—“She could excel if she tried harder.” Politeness also appears in formal emails or proposals: “Could you please review the attached files?” to maintain a courteous tone. Vary usage by mixing in synonyms like “might” or “would” as needed, but let “could” stay the default if you’re striking a balance between possibility and politeness. The key is pairing it with specific verbs or scenarios that clearly indicate timeframe (past, present, or hypothetical) so your reader follows whether you mean a real but uncertain future or a missed opportunity in the past.
Casual Conversation
In everyday talk, “could” is your friend for polite or tentative statements: “We could grab pizza tonight,” or “Could you lend me a hand?” It can sound less forceful than “can,” making suggestions or requests feel gentler—“Could you pick me up at the station?” When discussing the past, you might reflect on capabilities—“I could run faster in high school,” or “I wish I could have gone to the party.” For quick speculation—“That could be the answer”—it implies a possibility rather than certainty. It also pops up in daydreams or hypothetical scenarios—“We could travel the world if we saved enough money.” If you want more direct, confident language, opt for “can” or “will,” but if your aim is to show courtesy, open-mindedness, or hypothetical leanings, “could” slips in naturally. Among friends, it keeps the vibe soft and flexible, letting others chime in with agreement, alternatives, or readiness to commit to a different plan.
Etymology
The modern “could” evolves from Old English “cūþe,” originally the past tense of “can,” meaning “to be able.” Over centuries, changes in English grammar and pronunciation turned this into the distinct modal verb “could,” which now primarily expresses possibility, past ability, and polite or conditional contexts. This historical link underscores its relationship to “can”: both relate to capability, yet “could” implies a shift—either it’s referring to the past, or it’s adding a layer of uncertainty, politeness, or hypothetical nuance missing from the more direct “can.” Despite these evolutions, the core idea remains consistent: “could” retains that sense of potential or ability, albeit often softened, made conditional, or placed in the past tense of an otherwise straightforward “can.”