I saw the statement a few times that sign languages inflect in the same way that spoken languages do, but all examples I came across refer to phenomena that I would classify as word formation rather than actual inflection.
(Edit.) So my question is this: does any sign language possess a unit (hand or finger movement, facial expression, anything really) that:
- makes no sense if used alone,
- modifies the grammatical (syntactic, if you will) function of the word it is attached to,
- does not modify the semantics of the word it is attached to, and
- can be used with at least an entire group of words (see below).
My guess would be that notions such as case, number or gender could be expressed in this way. Or maybe some sign language requires some kind of agreement between e.g. an adjective and a noun?
Examples of what I'm not interested in: 1. ASL for 'person' used after a verb (because it makes sense if used alone); 2. and 3. exaggerating the ASL sign for 'big' to obtain 'huge' (because it's the semantics that is modified, not the grammatical function); 4. signing slow slower in ASL to denote 'very slow' (because it's limited to this one word).