One-syllable adjectives with comparative “more” instead of -er

One of the first rules an English learner learns is that the comparative degree of monosyllabic (one-syllable) adjectives is formed by adding -er to the adjective (and, similarly, the superlative is formed by adding -est). Nevertheless, there are a few exceptions.

The following monosyllabic adjectives virtually always take the “more” and “most” form instead of the endings -er and -est, probably because they were originally thought of as absolute (non-comparable) adjectives (that is, they were adjectives like “third”; nothing can be “more third” than something else), but later turned out to be used in a comparable manner in certain contexts:

• real – more real – most real
• right – more right – most right
• wrong – more wrong – most wrong
• ill – more ill – most ill
• worth – more worth – most worth
• prime (“main”, “important”) – more prime – most prime
• loath (“not willing to”) – more loath – most loath

The somewhat colloquial adjective “fun” cannot take the endings -er and -est either:

• fun – more fun – most fun

Furthermore, both forms are in use for the following adjectives:

• drunk (“intoxicated”) – more drunk / drunker – most drunk / drunkest
• cross (“bad-tempered”, “angry”) – more cross / crosser – most cross / crossest
• like (as in “they have like [similar] minds”) – more like / liker – most like / likest

Note also that adjectives formed from past participles of verbs cannot take the endings -er and -est:

• lost – more lost – most lost
• bored – more bored – most bored
• …

Even adjectives which normally take the endings -er and -est are, rarely, used with “more” and “most”, such as when contrasting “more” and “less”:

or when expressing contempt or disgust and strongly emphasizing the negative quality: