Will Vs be Going To

Sometimes we're confused by use of Will and Be going to in a sentence. When we've to use Will and  when we've to use Be going to. In this article, I wanna share 'bout that to you.

Use of Will
1. Show a willingness : give our will to do something for some one

    Ex : - I haven't sent your letter, I'll do it later
           - A : This room is so dark, isn't it?
              B : Yeah, I'll turn the lamp for you.
2. Spontaneous plan
    Our deciding to do or don't do something when people ask to us,
    but without preceded of thinking first.
    Ex : - A : If you won the lottery, what will you do?
              B : I'll buy a newest car and will round this world.
           - X : What will you have sir? (at the restaurant)
              Y : I'll have steak please.

3. Prediction With out clues
    Our prediction 'bout something but we don't have any clues 'bout it
    first, just talk nonsense.
    Ex : - You'll get a long life
           - It'll be rain. (we don't see any clouds in the sky)

Use of Be going to
1. Prior plan
    To show our plan which has pass thinking process first. Although it
    just a few minutes, but it had been considered has passed
    thinking process.
    Ex : - A : Why you turn on the TV?
             B : I'm going to watch some news.
           - A : Have you decided what color you want to paint
                   this room?
             B : Yes, I'm going to paint this room with the dark one.

2. Prediction with clues
    Our prediction 'bout something and we have any clues 'bout it first,
    we talk 'bout what we saw.
    Ex : - It's going to rain (We saw many clouds in the sky)
           - A : What do you want for lunch?
              B : Hmm, (thinking)
                   I'm going to have Fried chicken.

    Hope this article can help you in learning English. I precious if
    you give me critics and suggestions to make this blog more alive.
    Tq