Quick answer: Important means having great value, influence, or priority: This is an important decision. Significant means having a notable, often measurable effect or implication, especially in formal or academic contexts: There was a significant increase in sales. For a fuller definition, see the Cambridge Dictionary entry for ‘important’.
Comparison Table
| Word | Core meaning | Register | Example |
|---|---|---|---|
| important | high value or influence | all registers | Sleep is important for health. |
| significant | notable measurable effect or implication | formal / academic | The results were statistically significant. |
Understanding Important
Important is the broader, more everyday word. It suggests that something has high value, priority, or influence. It is used in all contexts — from casual conversation to formal writing. The noun form is importance and the adverb is importantly.
It is important to check your work before submitting.
She plays an important role in the team.
Health is more important than money.
More importantly, we need to act now.
Important People
When describing people, important suggests high status or influence: “She is an important figure in British politics.” Significant is rarely used to describe people in this way.
Understanding Significant
Significant stresses that something is notable, measurable, or meaningful in a specific context — especially in research, data, and formal analysis. It implies that the effect is large enough to matter or to be statistically meaningful. The noun is significance and the adverb is significantly.
There was a significant drop in crime rates.
The difference was not statistically significant.
This discovery has significant implications for medicine.
Sales increased significantly in Q4.
Common Mistakes
✗ It’s significant that you come to the meeting. (sounds overly formal or technical)
✓ It’s important that you come to the meeting.
✗ There was an important decrease in the infection rate. (possible but vague)
✓ There was a significant decrease in the infection rate. (implies measurable and notable)
✗ Significantly, this shows we must reconsider our approach. (odd as a discourse marker)
✓ Importantly, this shows we must reconsider our approach. (importantly = this point matters)
Also compare: Indicate vs Show, Expensive vs Costly, Certain vs Sure. Browse all confusing word pairs →
Quick Check: Important or Significant?
Four questions — choose the correct word.
1. “The study found a ___ link between sleep and memory.” (research context)
2. “It is ___ to drink enough water every day.” (general advice)
3. “Profits rose ___ in the second quarter.” (measurable change)
4. “She plays an ___ role in the organisation.” (describing influence)
Frequently Asked Questions
What is the difference between important and significant?
Important means having great value, influence, or priority. Significant means having a notable, often measurable, effect or implication — especially in formal or academic contexts.
Can significant be used in everyday speech?
Yes, but it sounds formal. In casual conversation, important is more natural: “That’s really important.” Significant fits better in professional or academic settings.
What does “statistically significant” mean?
In research, “statistically significant” means the result is unlikely to have occurred by chance and can be considered a genuine effect. This is a technical use of significant that has no equivalent with important.
Are the adverbs importantly and significantly interchangeable?
No. Importantly is used as a discourse marker to signal a key point: “More importantly, the project is on time.” Significantly modifies verbs and adjectives to indicate degree: “Costs fell significantly.”
Can important describe people?
Yes. “She is an important person in the field.” Significant is rarely used for people in this way — it would sound odd to say “She is a significant person.”
What are the noun forms?
The noun of important is importance: “the importance of education.” The noun of significant is significance: “the significance of the discovery.”
Is “a significant improvement” stronger than “an important improvement”?
Not necessarily stronger, but different in focus. “A significant improvement” emphasises that it can be measured and clearly noticed. “An important improvement” emphasises that it matters and has priority.
Can significant mean “large in quantity”?
Yes. “A significant amount of money” means a notable, large amount. Important cannot be substituted here: “an important amount of money” is unnatural.
What is the opposite of important?
The opposite of important is unimportant or trivial. The opposite of significant is insignificant or negligible.
Which is preferred in IELTS and academic writing?
In academic writing, significant is often preferred for describing data, results, and effects: “a significant rise in temperatures.” Important is preferred for expressing priority or relevance: “It is important to consider the ethical implications.”