Unlike most pairs of French and English words, adjectives ending in -ible often look identical, or nearly identical, in both languages. Possible is “possible”, terrible is “terrible”, and visible is “visible”. Both languages took this ending from the same source, the Latin ending -ibilis, added to a verb to describe something that can be done to it or by it. English mostly received these words by way of French rather than straight from Latin, which is why the spelling in the two languages stayed so close. Small differences still appear here and there, usually an added French accent, and a handful of pairs look alike but do not mean the same thing.

Below are the main groups of examples.

Words spelt the same in both languages

• Accessible – “accessible”
• Admissible – “admissible”
• Audible – “audible”
• Combustible – “combustible”
• Compatible – “compatible”
• Digestible – “digestible”
• Divisible – “divisible”
• Flexible – “flexible”
• Horrible – “horrible”
• Imperceptible – “imperceptible”
• Impossible – “impossible”
• Inaccessible – “inaccessible”
• Inadmissible – “inadmissible”
• Inaudible – “inaudible”
• Incombustible – “incombustible”
• Incompatible – “incompatible”
• Indestructible – “indestructible”
• Indivisible – “indivisible”
• Intangible – “intangible”
• Intelligible – “intelligible”
• Invincible – “invincible”
• Invisible – “invisible”
• Ostensible – “ostensible”
• Perceptible – “perceptible”
• Perfectible – “perfectible”
• Plausible – “plausible”
• Possible – “possible”
• Risible – “risible”
• Susceptible – “susceptible”
• Tangible – “tangible”
• Terrible – “terrible”
• Transmissible – “transmissible”
• Visible – “visible”

Words with small spelling differences

• Crédible – “credible”
• Éligible – “eligible”
• Infaillible – “infallible”
• Irrésistible – “irresistible”
• Irréversible – “irreversible”
• Lisible – “legible”
• Reproductible – “reproducible”
• Réversible – “reversible”

The French accent in words such as crédible and réversible is simply a spelling requirement before certain letter combinations, not a sign of a different origin. Lisible, from the French verb lire, “to read”, corresponds to “legible”, which comes from a different Latin verb with the same meaning. Illisible, built the same way, corresponds to “illegible”.

Words from a different root

• Comestible – “edible”

Comestible comes from the Latin verb for eating, comedere, while “edible” comes from a related but separate Latin verb, edere. The two words end up meaning the same thing without sharing the same root.

False friends and exceptions

A few pairs that look alike are worth extra care.

• Sensible does not mean “sensible” in French. It means “sensitive”, as in a person who is easily moved or a topic that needs careful handling. The English word “sensible”, meaning showing good judgement, is usually raisonnable or sensé in French.
• Négligeable corresponds to “negligible” in meaning, but ends in -eable rather than -ible.
• Responsable corresponds to “responsible” in meaning, but ends in -able rather than -ible.

Summary

French and English adjectives ending in -ible are usually spelt the same way and carry the same meaning, since both languages inherited the ending from the Latin -ibilis by a similar route. Small spelling differences appear in a handful of pairs, often through a French accent or a different Latin verb behind the word, as with lisible and “legible”, or comestible and “edible”. A small number of look-alike words, above all sensible, do not match in meaning and are worth learning as exceptions.