1. SPECULATIONS AND DEDUCTIONS

10. SPECULATIONS AND DEDUCTIONS WITH MODAL VERBS
IN THE PRESENT
MUST + INFINITIVE: He must be a teacher (He has lots of exams to correct)
MAY/MIGHT/COULD + INFINITIVE: He may/might/could be a teacher (He has a lot of holidays)
CAN’T / COULDN’T + INFINITIVE: He can´t be a teacher (He works at the weekends)

11. SPECULATIONS AND DEDUCTIONS WITH MODAL VERBS
IN THE PRESENT , but CONTINUOUS
MUST + CONTINUOUS INFINITIVE: He must be working now (It is five o’clock)
MAY/MIGHT/COULD + CONTINUOUS INFINITIVE: He may/might/could be working now (It is eight o’ clock)
CAN’T / COULDN’T + CONTINUOUS INFINITIVE: He can´t be working now (It is ten o’clock)

12. SPECULATIONS AND DEDUCTIONS WITH MODAL VERBS
IN THE PAST
MUST + PERFECT INFINITIVE: He must have had a cold (He has not come to class)
MAY/MIGHT/COULD + PERFECT INFINITIVE: He may/might/could have been ill (He has not come to class)
CAN’T / COULDN’T + PERFECT INFINITIVE: He can´t have been ill (He looks really healthy)