When we want to express permission, prohibition (not allowing something), obligation or no obligation we use modal verbs.
Permission – can, may, could
'Can' is most often used to ask for or give permission but 'may' and 'could' are also possible even though they are not used as often as 'can'.
Can I borrow a pen?
You can sit here, the seat is free.
Could I open the window?
May I ask a question?
The passive is formed by the verb be in an appropriate tense and the past participle (third form of the verb).
The perfect aspect
In American English it is very common to use the simple past tense instead of the present perfect which speakers of British English might use.
American English
I feel tired. I worked too much. I think I lost my keys. Did you see them anywhere?
Are you going to the show? No I already went.
You're looking for Jane. I just spoke to her.
Common uses of demonstratives.
In English the demonstratives; this, that, these and those are used to indicate something.
'The'- the definite article is the most frequent word in English.
We use 'the' when we think that the person we are talking to or writing to knows what we are referring to and when or because there is only one within the context or surrounding relevant to the conversation, or if there is only one in the world.
Many of us confuse the words only and just which is not really surprising especially since in some situations they are interchangeable as they can have the same use.
Here are the main uses of both words.
Only
'Only' has many different uses which makes it a very busy word. It can be an adjective, and adverb and a conjunction.
When we talk about something that happened in the past, we might want to refer to something that happened before that time. To do this we use the past perfect.
Look at these two sentences:
My friend left the bar at 10.00
I arrived at the bar at 10.30
We use the present perfect tense to talk about things where there is a connection between the past and the present.
He has worked with three different companies.
He started working sometime in the past. Up to now he has worked for three companies.
Look at the linking words in these sentences:
"They arrived home just as I was about to call the police."
just as – at the same time or at the start of another action.
"The workers stopped as soon as the bell rang."
as soon as – immediately after
