1. It’s easy to understand this text, isn’t it?
It was easy to understand this text yesterday, wasn’t it?
It will be easy to understand this text tomorrow, won’t it?
2. It’s interesting to listen to your stories.
It was interesting to listen to your stories last Friday.
It will be interesting to listen to your stories next Monday.
3. Is it difficult for you to learn grammar rules?
Was it difficult for you to learn grammar rules last week?
Will it be difficult for you to learn grammar rules nexy year?
4. It’s dark in the room, isn’t it?
It was dark in the room yesterday, wasn’t it?
It will be dark in the room tomorrow, won’t it?
5. It doesn’t often snow here in winter.
It didn’t snow here in winter last year.
It won’t snow here in winter next year.
6. It doesn’t rain here very often at this time of year.
It didn’t rain here very often at this time of year in 1999.
It won’t rain here very often at this time of year in 2017.
7. It’s important for me to finish the work today.
It was important for me to finish the work yesterday.
It will be important for me to finish the work tomorrow.