Will

• Will is a modal auxiliary verb. It is followed by an infinitive without to. There is no –s in the third person singular. She will come. (NOT She wills come.)
• I will do it.

Questions and negatives are made without do.

• Will you come with me? (NOT Do you will …)
• I will not let him go.

Uses

To express simple futurity

Will is used to talk about future events that you are certain about or things that are planned.

• Ann will be 10 years old next month. 
• There will be trouble if he catches you stealing his flowers. 
• The train leaves at 9:30, so we will be home by lunchtime. 

To talk about willingness

Will shows determination or willingness on the part of the speaker.

• I will come with you. 
• There is the doorbell. I will go. 
• We will not surrender.

Will can also express a promise or a threat.

• I will do whatever I can to help you.
• I will teach him a lesson.
• We will dismiss you from service.

To ask someone to do something

Will can be used to ask someone to do something.

• Ask John if he will help. 
• Will you lend me some money? 
• Will you give the book to John when you meet him? 

To make requests and offers

Will can be used as a polite way of inviting someone to do something or of offering someone something. Note that would is a more polite form of will.

• Will you join us for a drink? 
• Will you send me the report?

Won’t you is used to make a pressing offer.

• You will have some coffee, won't you? 

To give orders

Will can be used in orders.

• Will you be quiet? 
• If you don't behave, you will go straight to bed. 

To talk about possibility

Will can show possibility.

• ‘There is the doorbell.’ ‘That will be Sita.’