By vs Within
Use By with a point of time
Example: The assignment must be submitted by 12th March 2021.
Use Within with a period of time.
Example: These invoices must be paid within 2 weeks.
There is also another possibility to use in instead of within, they are synonymous.
The invoices must be paid in 2 weeks.
Have Been vs Have Gone
Have Been : If you have been to a place and returned.
Have Gone: if you have gone to a place and not returned yet.
Example: Where's Ram? He's gone to Kathmandu. He'll be back on Monday.
Hari has been to Pokhara, he bought me this gift.
On Time vs In Time
On time : at the planned time (not before nor after)
In Time : with enough time to spare (not later than the planned time)
Example: The bus was on time.
He arrived in time to catch the bus.
The project was completed on time.
We delivered the project report in time for the board meeting.
When using multiple adjectives
When using multiple adjectives they should follow this order.
Opinion - Size - Shape - Age - Colour - Nationality - Material - Purpose (OSSACNMP)
My husband has bought a big new white German sports car.
Ayushman is a handsome thin young man.
I always carry a square black plastic bag.
When using the verbs TELL, ASK, CALL and PHONE do not use the preposition to before the object.
Can you ask your friend if he knows the answer?
Let me phone my father.
Can you call me when you are ready to go?
He told me to keep quiet.