Bryatesle permits pro-drop both for subjects and objects. However, the pro-drop seems to adhere to certain principles. The subject and the object seem to have rather opposite principles, however.
Subject drop is possible under some circumstances. The main circumstance in which it occurs is when all these conditions are filled:
- the subject is the discourse topic
- it is definite and individuated
- it has had an explicit realization as a noun that also was the subject of the recentmost finite verb to have an explicitly stated subject
Another situation where pro-drop is permitted is:
- the subject is explicitly present with the leftmost verb in a clause with a subordinate verb, or is explicitly present with the non-subordinate verb regardless whether it is the leftmost or rightmost. In such a clause, any other verb with the same subject may entirely drop any realization of the subject.
The object has a slightly different distribution of permissible omissions. Any of the following conditions suffice:
- a discourse topic that is an object as well as an 'embedded subject' (thus, essentially, a discourse topic that would be having the secondary subject case if it were explicit). Thus "so-and-so forced X[discourse topic] sell the house" would come out as "so-and-so forced sell the house"
- a verb that cannot be intransitive, when there's a clear "discourse object" that also is the object of that verb, or when the discourse topic is the object of the verb.
- a verb that cannot be intransitive, and is 'semi-coordinated' with a previous verb that had an object. This semi-coordination generally takes the form of adverbials implying simultaneity, sequentiality, resumption or other causal connections.