one of the JJR + plural

Adding -er/-est to adjectives before or with plural nouns often creates nonstandard forms (funner, interestinger, user-friendlier). Below: clear rules, many wrong/right pairs, ready rewrites for work, school, and casual contexts, and quick memory hacks to fix sentences fast.

Quick answer

Use -er/-est for short, established single-syllable adjectives (tall → taller). For most multisyllabic adjectives, noun-derived adjectives (fun), -ing adjectives (interesting), and hyphenated compounds, use more/most (more interesting, most fun, more user-friendly).

1-syllable adjectives → usually -er/-est (big → bigger, fast → faster).
2+ syllables, -ing, -ful, -able, or noun-adjectives → more/most (more helpful, most enjoyable, more interesting).
Hyphenated compounds → use more + compound (more user-friendly), not user-friendlier.

Core rule - a simple decision flow

Quick checks: say the -er form aloud; if it sounds forced, use more/most. Count syllables: two or more → usually more/most. If the adjective is really a noun used as an adjective (fun, cost), prefer more/most.

Forced-sounding -er → more/most (interestinger → more interesting).
Noun-adjectives like fun → more fun (not funner).
Compound adjectives keep the hyphen after more: more user-friendly.

Wrong | Right: Wrong: She has the funner toys. |
Right: She has more fun toys.
Wrong | Right: Wrong: That's the interestinger chapter. |
Right: That's the more interesting chapter.

Grammar mechanics (short)

English uses synthetic comparatives (-er) for short adjectives and analytic comparatives (more/most) for longer or morphologically complex adjectives. Adding -er to multisyllabic or compound forms often makes awkward or nonstandard words.

Pronounceability: interestinger is clumsy → say more interesting.
Clarity with plurals: more + adjective + noun keeps the modifier separate (more reliable options).
Formality: more/most is safer in academic or professional writing.

Wrong | Right: Wrong: This approach is the efficientest. |
Right: This approach is the most efficient.

Real usage and tone

Nonstandard forms appear in casual speech and character voice for effect. They can work in dialogue or playful copy, but they hurt credibility in reports, resumes, and academic papers.

Casual: funner signals informality; fine among friends.
Creative: nonstandard forms can convey regional voice or age in fiction.
Professional: use more/most to preserve credibility.

Usage: Casual: "That day was funner than last year." →
Formal: "That day was more fun than last year."
Usage: Creative: "It was the funnest summer of her life." (character voice)
Usage: Professional: "The new protocol produced more reliable results." (avoid: reliabler)

Work writing - clear fixes for emails, reports, slides

Business writing needs clarity and professionalism. Replace nonstandard -er/-est forms with more/most and, when useful, rephrase to an active, measurable comparison.

Use more before hyphenated or multi-word adjectives: more cost-effective, more user-friendly.
When comparing features, make both items explicit: A is more X than B.
In slides, prefer concise alternatives: "more efficient" or "faster" (if single-syllable and standard).

Wrong | Right: Wrong: We launched a user-friendlier dashboard. |
Right: We launched a more user-friendly dashboard.
Wrong | Right: Wrong: This option is the costlier for Q2. |
Right: This option will cost more in Q2. | Alt: This option is more costly in Q2.
Wrong | Right: Wrong: The revised process is the fasterest. |
Right: The revised process is faster. | Alt: The revised process is faster than the previous one.

School and academic writing - formal rewrites and evidence-friendly phrasing

Academic contexts expect standard comparatives and support for claims. Replace casual -er forms with more/most and back superlatives with data or citation when possible.

Use more with multisyllabic adjectives (more significant, more informative).
When claiming most, provide evidence or a source.
Avoid colloquial comparatives in abstracts and formal sections.

Wrong | Right: Wrong: The experiment showed the interestinger trends. |
Right: The experiment showed more interesting trends.
Wrong | Right: Wrong: This sample was the reliabler one. |
Right: This sample was more reliable.
Wrong | Right: Wrong: That was the clearestest explanation in class. |
Right: That was the clearest explanation in class. | Alt: That explanation was clearer than the others.

Try your own sentence

Test the full sentence rather than the isolated phrase-context usually resolves whether a comparative is natural. Paste a sentence into a checker or read it aloud to judge tone and clarity.

Casual speech and messaging

Playful texts often tolerate funner/funnest, but mixed audiences will notice. Use more/most for a safer, cleaner casual tone.

Text to friends: funner is fine for playful tone.
Semi-formal chats (group with boss): use more fun.
Social posts: standard comparatives reach broader audiences.

Wrong | Right: Wrong: That movie was funner than I thought. | Right (clean): That movie was more fun than I thought.
Wrong | Right: Wrong: This burger is the tastierest. |
Right: This burger tastes better. | Alt: This burger is tastier.
Wrong | Right: Wrong: Their yard is the greenestest. |
Right: Their yard is the greenest in the neighborhood. (green → greenest is standard)

Fix your sentence - three paste-ready rewrites

Common problem sentences with two polished rewrites: one formal, one alternative phrasing you can paste into email, report, or post.

Problem (work): The new UI is user-friendlier. | Formal: The new UI is more user-friendly. | Alt: Users find the new UI easier to navigate.
Problem (school): His paper was interestinger than mine. | Formal: His paper was more interesting than mine. | Alt: His paper raised more compelling questions.
Problem (casual): That festival was the funnest ever. | Clean: That festival was the most fun I've ever had. | Casual alt: That festival was so much fun.

Memory tricks, hyphenation, and spacing

Three fast hacks: syllable test, forced-sound test, and the hyphen rule.

Syllable test: 2+ syllables → default to more/most (exceptions exist: clever → cleverer).
Forced-sound test: Say the -er/-est form aloud. If it jars, use more/most.
Hyphenation: Keep hyphens in compounds after more (more user-friendly). Never run words together (more userfriendly is wrong).

Usage: Hyphen: Wrong: more userfriendly |
Right: more user-friendly
Usage: Syllable: Wrong: She's the beautifuler candidate. |
Right: She's the more beautiful candidate.

Similar mistakes to watch for

Fixing -er/-est issues helps catch related errors: fewer vs less, adjective vs adverb confusion, and invented -er compounds.

fewer vs less: Use fewer with count nouns (fewer emails), less with mass nouns (less traffic).
Adjective vs adverb: more efficient (adj) vs more efficiently (adv) - choose based on whether you modify a noun or a verb.
Avoid invented compounds: don't write beautifuller or creativeer; write more beautiful, more creative.

Wrong | Right: Wrong: There's less emails this week. |
Right: There are fewer emails this week.
Wrong | Right: Wrong: She explained it more clearer. |
Right: She explained it more clearly. | Alt: She explained it more clearly than before.
Wrong | Right: Wrong: This tool is trustworthier. |
Right: This tool is more trustworthy.

FAQ

When is it ever OK to say "funner" or "funnest"?

They work in informal speech, casual texts, or intentionally colloquial writing. Avoid them in academic, formal, or professional contexts; use more fun / most fun instead.

Can I write "user-friendlier" in a product spec?

No. Prefer "more user-friendly" or "the more user-friendly option." Keeping the hyphen makes the compound clear and avoids a nonstandard -er form.

How do I choose between "more efficient" and "more efficiently"?

"More efficient" modifies a noun (a more efficient process). "More efficiently" modifies a verb (the team works more efficiently). Pick adjective vs adverb based on what you are describing.

Is "cleverer" correct?

Cleverer is accepted by many speakers because clever is short. Some two-syllable adjectives take -er, but when in doubt, use more clever or rephrase; in formal writing, more clever is often safer.

Quick editing trick to spot -er/-est mistakes?

Search your draft for comparatives with unfamiliar -er endings, read them aloud, and ask: does it sound natural? If not, replace with more/most or rephrase the sentence to remove the comparative.

Want a fast check of one sentence?

Paste a sentence into a context-aware grammar checker to flag nonstandard comparatives and get suggested rewrites. That saves time when polishing emails, reports, or posts.