This paper describes free relative constructions in Modern Standard Arabic (henceforth, MSA) and aims to provide an HPSG analysis for them. MSA has two types of free relative constructions. One, which is introduced by the complementizer ʔallaði , looks just like a relative clause. The other, which is introduced by the elements man and maa, which also appear to be complementizers, does not look like a relative clause. Both types can be analysed in term of unary-branching structures (as NPs consisting just of a CP). In ʔallaði free relatives, the NP and the value of SLASH can be coindexed via the value of MOD on the CP. In man and maa free relatives, the NP and the value of SLASH must be coindexed directly.
Keywords: Arabic, Free Relative, HPSG, SLASH