‘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