Use will to talk about the future. The form is the same for everyone: will + the base verb (no -s). When we speak, we often shorten it to 'll (I'll, she'll). Two common uses: a prediction (what you think will happen) and a promise or quick decision (what you will do).
will + verb
I will call you tomorrow. (a promise)
It will be sunny today. (a prediction)
She'll help you with your bags.
They will arrive at six.
Not "She wills come tomorrow." — say "She will come tomorrow.". will never adds -s, and the next verb stays in the base form (no "to").
Try it: Look at the sky. I think it ___ later. (will rain / will rains / rains) Answer: will rain — For a prediction about the future, use will + the base verb: it will rain. "will rains" adds an extra -s, and "rains" is the present, not the future.
won't = will not
For the negative of will, use won't + the base verb. (won't = will not.) It is the same for everyone, with no -s. Use it to say something won't happen (a prediction) or to say you won't do something (a promise).
I won't be late, I promise. (a promise)
Don't worry, it won't rain. (a prediction)
She won't come to the party.
Not "I don't will be late." — say "I won't be late.". The negative of will is won't, never "don't will".
Try it: Don't worry, I ___ tell anyone your secret. (won't / don't will / willn't) Answer: won't — The negative of will is won't + the base verb: I won't tell. "Don't will" and "willn't" are not real forms, the one word is won't.
Will you ...?
To ask about the future, or to ask someone to do something, start with Will + the person + the base verb: Will you ...?
Will you be at the meeting tomorrow?
Will you help me with this box?
Will they arrive on time?
Try it: ___ you be home this evening? (Will / Do / Are) Answer: Will — To ask about the future, start with Will: Will you be home? "Do you be" is not a real form, and "Are you be" doubles the verb be.
Put it together
Now use all three together: will + base verb for the positive, won't + base verb for the negative, and Will you ...? to ask. The verb after will/won't is always the base form.
I will call, but I won't be late.
Will you help me? Yes, I will.
It won't rain, so we will go out.
Try it: ___ you call me later? Don't worry, I ___ forget. (Will … won't / Do … don't will / Will … willn't) Answer: Will … won't — To ask, start with Will: Will you call me? For the negative, use won't: I won't forget. The question uses Will; the negative uses won't.