EGrammar - Unit 19 be going to do

I am going to do something = I have already decided to do it, I intend to do it;
"I be going to do something"はすでにそれをすることを決断している時に使います。

I head tha Lisa won some money. What is she going to do with it?
She is going to buy a new car.

This cheese looks awful. I am not going to eat it.

You can also say that something is going to happen in the future. For example

Look at those black clouds! It's going to rain. (The clouds are there now.)
I feel terrible. I think I am going to be sick. (I feel terrible now.)

比べてみよう、be doing / be going to do

We normally use "I am doing" when we say what we have arranged to do, and "I am going to do something" = I have decided to do it(but perhaps not arranged to do it)
Often the difference is very small, and either form is possible.
be doingはそれをすることを決めて、そうするように準備している時に、be going to doはそれをすることを決めただけの時に使います。と言っても、その差は小さく、あまり気にすることはありません。

What time are you meeting Amanda this evening?
I am leaving tomorrow. I have my plane ticket.

"The windows are dirty." "Yes, I know. I am going to wash them later." (= I have decided to wash them, but I haven't arranged to wash them)

was/were going to do something

be going to doがすることを決めただけ、を意味することから過去形でも使うことが出来ます。この場合、することを決めていたけど、しなかった、という意味を言外に示します。
I was going to do something = I intended to do it but didn't do it.

We were going to travel by train, but then we decided to drive instead.
I was just going to cross the street when somebody shouted, "Stop!"

単語

run out (of a supply, of something)

be used up, become no longer valid

intend

[trans]
have (a course of action) as one's purpose or objective; plan
design or destine (someone or something) for a particular purpose or end

awful

very bad or unpleasant, extremely shocking, horrific
inspiring reverential wonder or fear

reverential

adjective
of the nature of, due to, or characterized by reverence

disgust

noun
a feeling of revulsion or profound disapproval aroused by something unpleasant or offensive