soon, early and quickly

soon

Soon means ‘a short time after now’ or ‘a short time after then’.

• Get well soon. (not Get well early.)
• The work was hard at the beginning, but she soon got used to it.
• ‘I’ll pay you soon.’ ‘The sooner the better.’

note

For no sooner … than, (see here).

early

The adverb early means ‘near the beginning of the time-period that we are thinking about’. It does not usually mean ‘a short time after now/then’.

• Early that week, Luke was called to the police station.
• We usually take a long break early in the year. (not … soon in the year.)
• I usually get up early and go to bed early. (not I usually get up soon …)

Sometimes early means ‘before the expected time’.

• The plane arrived twenty minutes early.

Early can also be used as an adjective.

• I caught an early train.
• You’re very early.
• It’s the earliest known example of a cave painting.

In a formal style, the adjective early can sometimes have the same kind of meaning as soon.

• I should be grateful for an early reply.
• Best wishes for an early recovery.

A watch or clock is fast or slow, not early or late.

• My watch is five minutes fast.

quickly

Quickly refers to the speed with which something is done. Compare:

• Let’s get her to the doctor quickly. (It’s urgent – we need to move fast.)
  I ought to see the doctor soon. (not an emergency)
• He did the repair quickly but not very well.
  I hope you can do the repair soon – I need the car.