Let's do a quick lesson on when to use the word will and when to use the phrase going to in English.
One situation in which we use the word will is when we decide right now that we're going to do something in the future.
For example, if your friend tells you that he's going to the movie theater later today and you think that sounds like a good idea, you might say I'll go too.
You're making that decision right now, so you say, I will or I'll.
Another time when we like to use will is when we're promising something or offering something.
For example, I could say, I promise I will never tell anyone your secret.
And I could say, I'll help you with your homework if you're having trouble.
In the first example, I'm promising to keep the secret.
And in the second example, I'm offering help.
So I can use the word will.
Another instance when we sometimes use will is when we make a prediction about the future, especially when we use the phrases I think, I believe, I predict, etc.
For example, someone could say, I think that Portugal will win the next World Cup.
However, it's also common to use the phrase going to for predictions.
So you could also say, I think that Portugal is going to win the next World Cup.
And we also like to use will when talking about a future fact.
Not just a prediction or opinion or plan, but an actual fact.
Like for example, next year will be my tenth year of teaching English.
So these are some of the main situations in which we use the word will.
There are other situations, but these are probably the most common.
How about going to?
We use this phrase when talking about something that we already intend to do in the future.
We didn't just make the decision right now.
We already made the decision earlier.
For example, I could say I'm going to take my son to the dentist next week.
This is a plan that I already made before this moment.
So when you're talking about your plans or things that you're gonna do in the future, you're probably gonna use the phrase going to a lot more than will.
Also, it's common to just use the present continuous tense instead of going to when talking about your plans.
For example, instead of saying I'm going to visit my cousin next week, I could also say I'm visiting my cousin next week.
But I wouldn't say I'll visit my cousin next week, unless perhaps I'm making my plans right now and I'm deciding when I might possibly visit my cousin.
So we use going to to talk about things we already intend to do in the future.
And we also use going to to talk about things that we're certain are going to happen in the future.
For example, I could say it's going to rain soon.
This is technically a prediction because it's not an established fact, but I'm certain that it's going to happen, because I see dark clouds approaching and my weather app says that there's a 100 chance of rain.
We can also use going to for less certain predictions like I think Portugal is going to win the next World Cup.
But as I mentioned earlier, we can also use will in this case.
There are probably other situations in which we might use the phrase going to, but these are the most common ones.
So now you know when to use will and when to use going to.