ESEN
Which one to use?Intermediateadjectivenoun
RationalvsRationale
'Rational' is the adjective meaning based on logic; 'rationale' is the noun for the reasoning behind a decision.
Side-by-side comparison
Rational
adjective"Rational" (adjective) describes something based on reason and logic, not on emotion. "A rational decision" = a well-reasoned, logical decision. The opposite of "irrational".
A rational approach to the problem requires setting aside personal feelings and focusing on the data.
It is not always rational to choose the cheapest option, quality and long-term cost matter too.
She remained calm and rational throughout the crisis, which helped steady the rest of the team.
Rationale
noun"Rationale" (noun) is the underlying reason or justification behind a decision or plan. "The rationale for the change" = the logical reasons explaining why the change was made.
The CEO presented the rationale for the merger in a company-wide address that lasted two hours.
Before approving any budget request, the committee requires a clear rationale from each department.
There was no obvious rationale for the policy change, which frustrated staff across all divisions.
Common mistake
- •"Please explain the rational behind your proposal" is wrong (correct: rationale, the noun meaning the reasoning).
- •"Rational" is always an adjective and cannot function as a noun in this sense.
Trick to remember it
- •"RationAL" ends in -AL like "logicAL," "practicAL," "criticAL", all adjectives.
- •"RationalE" adds an E, the E stands for Explanation: it IS the reasoning/justification itself.
Quick rule
- •Is it the adjective describing something based on reason? "Rational".
- •Is it the noun meaning the reasoning or justification? "Rationale".
Did you know?
Both words descend from Latin "ratio" (reason, calculation, account), the same root as "ratio" (mathematical proportion), "reason," "ration" (a calculated portion), and Spanish "razón." RATIONALE entered English from Medieval Latin "rationale" in the 17th century with the meaning "exposition of underlying principles." RATIONAL arrived earlier, in the 14th century. The confusion between the two is especially common in the contexts where both are most used: academic writing, business reports, and legal documents. A pronunciation note: RATIONALE sounds like /ˌræʃəˈnɑːl/ in English, it rhymes approximately with "national ale."
Practise what you learned
Exercise 1 · Pick the right one
His decision to leave early was completely _____ given how tired he was.
Exercise 2 · Pick the right one
Could you explain the _____ behind the new company policy?
Exercise 3 · Form the word
Related word pairs
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"Above" is at a higher level without contact; "over" implies covering, movement, or crossing.
ActuallyvsReally
"Actually" corrects or contrasts an assumption; "really" intensifies or confirms.
ActuallyvsCurrently
'Currently' means 'at the present time'; 'actually' means 'in reality', not 'nowadays'.
AdoptvsAdapt
'Adopt' means to take something on as your own; 'adapt' means to adjust to something new.
Bryan López
Founder of SpeakUP Academy