Long is most common in questions and negative sentences, and after too and so.

• How long did you wait?    
• I didn 't play for long.
• The concert was too long.

In affirmative sentences, we usually use a long time.

• I waited (for) a long time (I waited long is possible, but not usual.)
  
• It takes a long time to get to her house.

Much, many and far are also more common in questions and negative sentences.

We usually use roundior movement or position in a circle, or in a curve.

• We all sat round the table.
  
• I walked round the car and looked at the wheels.
  
• 'Where do you live?' 'Just round the corner.'
  

clause + after + clause after + clause, + clause

We can use after to join two clauses. We can either say: В happened after A happened
OR After A happened, В happened. The meaning is the same: A happened first. Note the comma (,) in the second structure.

We use in case to talk about things we do because something else might happen.

• Take an umbrella in case it rains. (= . . . because it might rain.)
• I've bought a chicken in case your mother stays to lunch.
• I wrote down her address in case I forgot it.

After in case, we use a present tense with a future meaning.

• ... in case it rains. (NOT . . . in case it will rein.)
  

We can also use should + infinitive. In this structure, should means 'might'.

• I've bought a chicken in case your mother should stay to lunch.
• I wrote down her address in case I should forget it.
  

The structure with should is more common in the past.

Don't confuse in case and if. 'I do A in case В happens' = 'I do A first because В might happen later.' A is first. 'I do A if В happens' = 'I do A if В has happened first.' В is first. Compare:

• Let's get a bottle of wine in case Roger comes.
  (= We'll buy some wine now because Roger might come later.)
  
• Let's buy a bottle of wine if Roger comes.
  (= We'll wait and see. If Roger comes, then we'll buy the wine. If he doesn't we won't.)

We use sorry for . . . -ing or sorry about . . . -ing to talk about past things that we regret.

• I'm sorry for/about waking you up. ( = I'm sorry that I woke you up.)

We can use a perfect infinitive with the same meaning.

• I'm sorry to have woken you up.
  

Sorry + infinitive is used to apologize for something that we are doing or going to do.

• Sorry to disturb you — could I speak to you for a moment?
• I'm sorry to tell you that you failed the exam.