1. Passive forms
Use: Past Simple Passive when we don’t know who did something.
straw was made in the 1930s somewhere in the United States.
Passive forms are used in news reporting, scientific writing and other kinds of writing where we are more interested in events and processes than in the person doing the action.
When the situation is in the present . the passive form of the verb plus the infinitive:The President is believed to be in contact with the Russians.
Same situation in the past ,passive plus the pastinfinitive:He is said to have poisoned his opponents in order to gain power.
2. Second, third conditionals
The second conditional is used to talk about unlikely or imaginary states or events in the present or future (form = if + past simple/continuous + would/could/should/might).
They would leave their jobs tomorrow and travel the world if they had the money.
The third conditional is used to talk about imaginary states or events in the past (form = if + past perfect + would/ could/should/might + have + past participle).
If they had studied other cultures at school, they might have been more confident about travelling.
A third conditional cause is sometimes linked to a second conditional result to show the imaginary present result of an imaginary past event or situation.
If my parents had never met, I wouldn’t be here now!
(A second conditional cause is sometimes linked to a third conditional result to show how an ongoing situation produced an effect in the past. If he knew about computers, he would have applied for that IT job.)
3. Wish/Would Rather
A. Talking about the past – things you regret doing/not doing:
wish + past perfect
Many parents wish they had not been so strict with their children when they were very young.
B. Talking about the present – things that haven’t come true and things that might come true in the future:
wish + past simple
(Both were and was are acceptable but were is more formal.)
They wish they were lying on a beach somewhere instead of being here.
Numerous IT students wish they were working for companies instead of constantly preparing for exams.
C. Talking about irritating habits – things which are annoying you:
wish + would
He wishes his daughter would make smarter decisions.
D. Would rather + past perfect
is used to talk about wishes in the past.
She’d rather had gone to an Italian restaurant.
E. Would rather + infinitive
without to is used to talk generally about wishes in the present and future.
The government would rather not give out too many benefits to young people.
4. Modals for speculation
could, might, may used to speculate about something the speaker or writer is unsure about:
It could be a possible reason for air pollution, though the scientists are still doubtful.
can’t/cannot and couldn’t/could not used to indicate certainty, in relation to impossible ideas and situations:
Banning fossil fuels completely cannot be one of the possible solutions for improving energy efficiency.
could have, might have, may have are used to express uncertainty about something in the past.
The dinosaurs may have survived without the meteor impact that seriously altered weather patterns at the time.
must have is used to express near-certainty about something in the past.
It must have been bitterly disappointing for those citizens who had hoped for political change.