"Will" vs "going to"

If we don't gain altitude the plane [?] crash

• is going to

• will

Answer explanation

The person saying this can see that the plane is too low and this might lead it to crash. Therefore, this is a prediction based on evidence.

Our neighbours [?] go away to Ireland for a vacation.

• are going to

• will

Answer explanation

This is something the neighbours of the speaker have planned. We use "going to" to speak about future plans.

In the future, cars [?] fly.

• are going to

• will

Answer explanation

There is no evidence of cars flying in the future. This is the speaker's opinion and so we use "will".

This cream [?] go bad soon, look at the expiration date!

• is going to

• will

Answer explanation

The speaker is surprised because they just saw the expiration date. This is the evidence used to predict that the cream is going to go bad. When we make predictions based on evidence, we use "going to".

I am only 12 years old, but I know I [?] be the president of Spain when I grow up.

• 'm going to

• will

Answer explanation

12-year-olds can't be candidates in presidential elections, so we know the speaker isn't looking at polls on their performance to make this prediction. This is just the speakers opinion, so we use "will".

Of course he [?] enjoy the party, who doesn't like dancing?

• is going to

• will

Answer explanation

This is a prediction based on what the speaker believes or, in other words, their opinion. When we make predictions based on opinion we use "will".

Our car [?] run out of fuel if you don't stop at a gas station soon.

• is going to

• will

Answer explanation

The speaker can see the fuel gauge (the thing that indicates how much fuel the car has left) and so this prediction is based on that evidence. We have to use "going to".

He [?] buy a new bike with his savings.

• is going to

• will

Answer explanation

We use "going to" because this is a future plan.

They [?] plant flowers in the garden next weekend.

• 're going to

• will

Answer explanation

We use "going to" because this is a future plan.

I'm sure she [?] like the gift we bought for her.

• is going to

• will

Answer explanation

Even if the speaker says they're sure of it, this is still an opinion. We use "will" for predictions based on opinion.