An Inventory of Cross-Linguistic Generalizations
1st/2nd person > 3rd person > proper name/kinship terms > human > non-human animate > inanimate
In a direct-inverse system, use direct verbal marking when the agent is higher than the theme in this hierarchy; use inverse verbal marking when the agent is lower than the theme in this hierarchy.
A verb does not assign accusative case unless it can assign a theta role to an external argument.
There is correlation between object shift and verb movement. A direct object can move out of VP only when there is verb movement.
Unidirectionality of Grammaticalization
There is a very strong tendency for grammaticalization to proceed in one direction. Once morphemes begin semantic bleaching they continue such bleaching until they are fully grammaticalized.
Word order, Prepositions and Postpositions
When considering languages that utilize adpositions, SVO languages are more likely to have prepostions than SOV languages, which are more likely to have postpositions.