Persian is usually assumed to lack a nonfinite clause, as its morphosyntactically distinguished infinitival form is a nominal infinitive. This paper takes a closer look at Persian modal verbs, which, in their impersonal use, take a seemingly past stem or third person singular verb as their complement. We show that the modal syntax of Persian reveals the existence of another type of infinitive in Persian which existed in the earlier stages of the language as well. This infinitive, which has been traditionally called the apocopated infinitive, is clausal in nature. We propose an LFG analysis for modal syntax in Persian, and show how our analysis captures marginal agreement patterns a related raising phenomenon.
Dashti et al. (Sun,) studied this question.