I'm trying to grok ASL's grammar. There seems to be a lot of folk grammar and the professional liguists haven't been studying it for very long so there is a lot of contradictory statments about what the basic word orders are in ASL.
Okay, if we have a language that is topic-comment, then the patient and the agent can be fronted and it seems like
1) A (agent) hit B (patient) -> A (topic), (omitted agent) hit B
2) A (agent) hit B (patient) -> B (topic), A hit (omitted object)
But the topic-comment versions of 1) & 2) look just like SVO and OSV.
What diagnostics tests are used to figure out the basic word orders (basic morphosyntactic alignment)?