A restrictive relative clause is one which restricts the possible entities that the head-noun of the relative clause can refer to. A non-restrictive relative clause provides additional information without narrowing down the set of entities that the head noun refers to. LSF instantiates both semantic types of relativization strategies, but the availability of each reading depends on the relative pronoun that is used. Relative clauses introduced by pi receive a restrictive interpretation, as shown in the following example. As a result, they cannot modify a proper name.
rel
ix1 prefer dog pi man pet
'I prefer the dog which the man pets. (Hauser, 2019: 66)
Additionally, as is typical of externally headed restrictive relative clauses, pi-relatives can stack and be embedded into each other. In the following example, the clause boundaries of each relative clause are represented with square brackets, and the co-reference between head nouns and relative pronouns is indicated through coindexation.
rel rel
a. mani fork-form sting pij dogj[chase catk [pik bird catch ]]
‘The man stabbed the dog which was chasing the cat which caught the bird.’
foc
rel rel
b. ix1 choose cati [pii play with girlj ] [pii catch birdk]
‘I choose the cat which is playing with the girl which caught the bird.’ (Hauser, 2019: 66)
Relative clauses introduced by person-cl receive an appositive interpretation, as shown by their compatibility with proper names head. This is a typical property of appositive relative clauses. person-cl-relatives cannot stack.
rel
ix1 prefer Mary person-cl pet the dog
‘I prefer Mary, who pets the dog.’ (Hauser, 2019: 67)
Regarding non-human or inanimate heads, only the non-manual marking strategy can give access to both appositive and restrictive readings.