Cool MateRational vs Reasonable
When to use each in English, with meaning, register, and examples.
Rational
Top 2,000 (common)C1adjective
Reasonable
Top 2,000 (common)B2adjective
| Rational | Reasonable | |
|---|---|---|
| Pronunciation | 🇬🇧 /["/ˈræʃnəl/"]/🇺🇸 /["/ˈræʃnəl/"]/ | 🇬🇧 /["/ˈriːznəbl/"]/🇺🇸 /["/ˈriːznəbl/"]/ |
| Meaning | Based on reason and logic. | Fair and sensible; not extreme. |
| Example | She gave a rational explanation for her decision. | It is reasonable to assume that the meeting will start on time. |
| Register | Neutral | Neutral |
| How common | Top 2,000 (common) | Top 2,000 (common) |
| CEFR level | C1 | B2 |
| Part of speech | adjective | adjective |
| Collocations | be, seem, highly, very, completely, about, be, seem, highly, very, completely, about | appear, be, look, extremely, fairly, very, appear, be, look, extremely, fairly, very, appear, be, look, extremely, fairly, very |
| Antonyms | irrational, illogical, unreasonable | unreasonable, irrational, excessive |
| Common mistakes | 'Rational' is often confused with 'rationale', which means the reason for something., Some learners might use 'rational' to refer to emotions instead of logic., Incorrectly saying 'more rational' when 'more rational than' is needed for comparison. | Confused with 'rational' which is more about logic than fairness., Using 'reasonable' to describe an extreme opinion or action., Incorrectly spelling it as 'resonable'. |
| Usage notes | Use 'rational' when describing thoughts or actions based on logic rather than emotions. It is appropriate in both formal and casual contexts, but may sound too technical in a relaxed conversation. | Typically used to describe actions, opinions, or decisions that are logical. Avoid in overly emotional contexts or when discussing extreme views. |
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Frequently asked questions: Rational vs Reasonable
What's the difference between Rational and Reasonable?
Rational: Based on reason and logic. Reasonable: Fair and sensible; not extreme.
Which is more advanced: Rational and Reasonable?
Rational is the highest level, at C1, on the CEFR scale.
Are Rational and Reasonable the same CEFR level?
Rational: C1, Reasonable: B2 on the CEFR scale.
What part of speech are Rational and Reasonable?
Rational: adjective, Reasonable: adjective.
Can you show an example of each?
Rational: She gave a rational explanation for her decision. Reasonable: It is reasonable to assume that the meeting will start on time.
Can I use Rational and Reasonable interchangeably?
Not always. Rational and Reasonable are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.