1. Principles & Parameters Approach in Linguistics - III
Bibhuti Bhusan Mahapatra

2. The clause structure 9) S  COMP NP INFL VP INFL [± Tense]
Comp  {[± WH]/for}

3. Subject is obligatory in English
10) i. There is a good reason for his refusal.
ii. I believe there to be a good reason for his refusal.
iii. I believe it to have rained.
iv. I would prefer its raining in September.
The italicized elements bear no theta roles.
11) *I would prefer my raining in September.
(11) suggests that the subject position of its embedded clause cannot be an argument position

4. Subject may not be obligatory in other languages
The subject is obligatory in English, but not obligatory in Italian and Spanish.
12. pro sono contento.
The subject is obligatory or not is a possible parameter. The parameter is called pro-drop parameter.

5. Thank You