Ambiregular verb

From Teflpedia

An ambiregular verb is a verb that has both an attested regular inflection, and an irregular inflection.

In English, there are a few of these. All of them are lexical verbs. Some uses are restricted to regional standards, e.g. British English or American English.

For example, the preterite and past participle of Learn can be either "learned" or "learnt".

For a list see category:Individual ambiregular verbs