Editing Suppletion (section)

=== Weak suppletion ===
The term "weak suppletion" is sometimes used in contemporary synchronic morphology in reference to sets of stems whose alternations cannot be accounted for by [[Synchrony and diachrony|synchronically]] [[Productivity (linguistics)|productive]] phonological rules. For example, the two forms ''child''/''children'' are etymologically from the same source, but the alternation does not reflect any regular morphological process in modern English: this makes the pair appear to be suppletive, even though the forms go back to the same root.

In that understanding, English has abundant examples of weak suppletion in its [[English irregular verbs|verbal inflection]]: e.g. ''bring''/''brought'', ''take''/''took'', ''see''/''saw'', etc. Even though the forms are [[Germanic strong verb|etymologically related]] in each pair, no productive morphological rule can derive one form from the other in synchrony. Alternations just have to be learned by speakers — in much the same way as truly suppletive pairs such as ''go''/''went''.

Such cases, which were traditionally simply labelled "[[Inflection#Regular|irregular]]", are sometimes described with the term "weak suppletion", so as to restrict the term "suppletion" to etymologically unrelated stems.