Future Predictions

If you think something is possible in the future, you are making a prediction.

I think England will win the next World Cup.

These are the most common expressions for making predictions. The percentages (%) arevery approximate - just to show you the order of the expressions.

It'll definitely rain.	100% chance of rain
It'll almost certainly rain. It's bound to rain.	90%-99%
It'll probably rain. It's likely to rain.	80%-95%
It'll possibly rain. It might rain.	50%-80%
It might not rain.	20%-50%
It probably won't rain. It isn't likely to rain.	5%-20%
It almost certainly won't rain.	1%-5%
It definitely won't rain.	0% chance of rain

Notice the position of words like "definitely" - before "won't", but after "will".

We often use 'be going to' instead of 'will' for predictions. There usually isn't a difference, but 'be going to' can mean that we have a reason for making the prediction.

I think it'll snow next Christmas.

(but that's in 12 months - I can't know this)

I think it 's going to snow again tomorrow.

(there are a lot of clouds and the weather is very, very cold)

The teacher thinks you'll speak perfect English one day.

http://www.tinyteflteacher.co.uk/learning-english/grammar/future-predictions.html