English tense usage

English tense usage
English tenses have two elements of meanings: time and aspect.
Time
1.The time referred to is usually obvious.
English people drink tea. (all time)
Shh! I m watching this programme! (now)
I ll see you later. (future)
I went out with Jenny last night. (past)
2.Sometimes a present tense form can refer to future.
I am going out tonight. (Present continuous for near future)
The train leaves at 10.00 tomorrow. (Present simple for a timetable)
If you see Peter, say hello from me. (Present simple in a subordinate clause)
3.Sometimes a past tense form can refer to the present.
I wish I could help you, but I can t.
The simple present
1 The simple present describes an action that is seen to be complete.
The action is viewed as a whole unit.
The sun rises the east. (= all time)
When I ve read the book , I ll lend it to you. (=complete)
She has red hair. (=permanent)
He always wore a suit . (=a habit)
It rained every day of our holiday . (= the whole two weeks)
This shop will close at 7.00 this evening . (= a fact)
2 The simple aspect expresses a completed action. For this reason we must use the simple , not the continuous , if the sentence contains a number that refers to things done .
She s written three letters this morning
I drink ten cups of tea a day.
He read five books while he was on holiday.
The Continuous aspect
1. The Continuous aspect focuses on the duration of a activity. We are aware of the passing of time between the beginning ad the end of the activity. The activity isn t permanent.
I m staying with friends until I find a flat. (=temporary)
What are you doing on your hands and knees? (= in progress)
I ve been learning English for years.(And I still am.)
Don t phone at 8.00. We ll be eating. (= in progress)