Book from Edinburgh University Press: North East Vernacular English Online
The Survey of English Dialects records a number of non-standard noun plurals. For example, the following are attested for Nb or Du or both: calfs, hoofs, sheafs, eyen, shoon, starn (Upton et al. 1994: 481-83). Forms preserving the Middle English -en plural are not found in RTG. However, there is some evidence in the corpus for the analogical levelling of the stem alternation in, for example, knife-knives > knife-knifes, which Wright (1905: 261) particularly associates with southern Scotland.
(1) I hate people who have to use knifes instead of fists to settle a problem (2015)
(2) A pleasant Sunday stroll on the hunt for conkers and leafs (2011)
(3) I can see why there’s an issue with killing bull calfs (2018)
(4) There might be dog thiefs out there (2018)
Example 5 represents a widespread feature across the dialects of England recorded in SED: plural forms with zero ending when preceded by a cardinal number, though these are lexically restricted to nouns of measurement and quantity in RTG.
(5) I bought the gaff ten year ago (2018)
SED also notes ‘double plurals’, but where they occur in RTG they could be jocular (e.g. mices), with the exception of folks.
(6) What’s on the menu today folks? (2018)
Collective singular forms are also widespread in SED, particularly in relation to livestock/animals used for food (e.g. pig). But this usage is only marginally dialectal.
References
Upton, Clive, David Parry and J.D.A. Widdowson. 1994. Survey of English Dialects: The Dictionary and Grammar. London: Routledge.
Wright, Joseph. 1905. The English Dialect Grammar. Oxford: Henry Frowde.