Linguistics: What is the redundancy rule?

Answer 1

Redundancy is a principle of grammar whereby grammatical features are often marked in more than one way and more than one place in a sentence. For example, in English we say "three dogs". Plurality is marked in two places in that phrase--"three" and "-s", thus plurality is redundantly marked. In Hungarian, however, they don't mark plurality redundantly--"három kutya" ('three dog') or "kutyák" ('dogs'), but NOT *három kutyák ('three dogs'). Redundancy can use phonological information, morphological information, and syntactic information to redundantly mark many features of the grammar.

Answer 2

I believe it refers to the fact of grammar having strict rules that help one understand meaning. At least, that's what Wikipedia is telling me. This is the example they give, which seems to explain it a lot better, even though it still doesn't give a n actual 'rule' about redundacy:

On the phonological level, the redundancy of phonological rules may clarify some vagueness in spoken speech; "a speaker may know that 'thisrip' must be 'this rip' and not 'this srip' because the English consonant cluster 'sr' is illegal'".

I hope that helps you; I'm all confused about it.