‘So’ and ‘such’ are often used incorrectly in English.

Both so and such are used to ‘give emphasis’ – this means to show that something is ‘extreme’ or ‘more than’. For example –

The concert was so good! It was such a good concert!

In both cases, it wasn’t simply a ‘good’ concert, it was more than that.

So and such rule #1:

The main difference between so and such is that you do not use a noun after ‘so’.

The concert was so good! This is correct

It was so a good concert You cannot say this

So and such rule #2:

After such, you need a noun.

It was such a good concert This is correct

It was such good You cannot say this

So and such rule # 3:

The two rules for so and such above can be combined with ‘that’ to talk about the results of something.

FACT = The concert was so loud. RESULT = our ears hurt.

The concert was so loud that our ears hurt. This is correct

The concert was such loud that our ears hurt. You cannot say this

It was such a loud concert that our ears hurt. This is correct

It was so a loud concert that our ears hurt. You cannot say this

So and such rule #4:

So can also be followed by an adverb. NOTE: This is used to make a short comment or exclamation about something.

He eats so quickly! This is correct

He eats such quickly! You cannot say this

She sings so beautifully! This is correct

She sings such beautifully! You cannot say this

He speaks so eloquently. This is correct

He speaks such eloquently. You cannot say this