SO, SUCH AND THIRD CONDITIONAL

SO and SUCH often have the same meaning : 'very' or 'to this degree'.

So is used before an adjective or an adverb (without a noun after it):

§  so big

§  so carefully

Such is followed by 'a' or 'an', + an adjective + a singular noun : 

§  such a long time

§  such an incredible story

Such is used without a, an before plural nouns, mass nouns (luggage, furniture)
and abstract nouns (advice, courage, generosity, kindness ... )

§  such fools

§  such (beautiful) furniture

§  such generosity

Compare the following sentences:

§  This book is so interesting.

§  This is such an interesting book.

§  Such interesting books are hard to find.

§  I was amazed that the crowd was so big.

§  I was amazed that there was such a big crowd.

§  Such big crowds can be frightening.

§  The story was so complicated.

§  It was such a complicated story.

§  Such complicated stories are difficult to follow.

§  You are so intelligent.

§  You are such an intelligent person.

§  A person of such intelligence is a pleasure to meet.

So ... that and such ... that are used to describe reasons and results.
So + adjective + that :
◊ The hotel was so comfortable that we decided to stay another night. 
Such + adjective + noun + that :
◊ It's such a comfortable hotel that we'll definitely stay there again. 

We can use the Third Conditional to talk about 'impossible' conditions, impossible because they are in the past and we cannot change what has happened.

·         If I had worked harder at school, I would have got better grades.

·         If I had had time, I would have gone to see him. But I didn't have time.

·         If we had bought that house, we would have had to rebuild the kitchen.

·         If we had caught the earlier train, we would have got there on time but we were late.

Notice that the main clause can contain 'would', 'could' or 'might.

·         If I had seen him at the meeting, I would have asked him. (But he wasn't there so I didn't.)

·         If I had seen him at the meeting, I could have asked him. ( But he wasn't there so it wasn't possible.)

·         If I had seen him at the meeting, I might have asked him. (But I'm not sure. Perhaps if the opportunity had arisen.)

·         If I had paid more attention in class, I would have understood the lesson.

Also notice that sometimes the 'if clause' is implied rather than spoken.

·         I'd have done it. ("if you had asked me but you didn't.")

·         I wouldn't have said that. ("if I'd been there.")

·         He wouldn't have let him get away with that. ("if he had tried that with me.")