1. A new grammar rule is always explained by the teacher. - Present Simple Passive
2. A new grammar rule was explained by the teacher yesterday. - Past Simple Passive
3. ..... rule will be explained by the teacher tomorrow. - Future Simple Passive
4. .. rule is being explained by the teacher at the moment. - Present Continuous Passive
5. ... rule was being explained by the teacher at 10 o'clock yesterday. - Past Continuous Passive
6. A new grammar rule has been explained by the teacher today. - Present Perfect Passive
7. By the time of our arrival a new grammar rule had been explained by the teacher. - Past Perfect Passive
8. A new grammar rule will have been explained by the time of our arrival. - Future Perfect Passive
1. The poem is often learnt by the boy. - Present Simple P. ( P. = Passive)
2. The poem was learnt by the boy the day before yesterday. - Past Simple P.
3. The poem will be learnt by the boy next Monday. - Future Simple P.
4. The poem is being learnt by the boy now. - Present Continuous P.
5. The poem was being learnt by the boy at 7 o'clock yesterday. Past Continuous P.
6. The poem has just been learnt by the boy. - Present Perfect P.
7. The poem had been learnt by the boy before parents came. - Past Perfect P.
8. The poem will have been learned by the boy before Christmas. - Future Perfect P.