After as a preposition and conjunction
After means ‘later than’ and ‘next in time or place’.
After can be used before a noun phrase (as a preposition):
Shall we have a swim after lunch?
The bank is just after the park, on the left.
After can introduce a clause (as a conjunction):
After I left him a message, he phoned me immediately.
She did voluntary work in a hospital after she graduated.
We use the present simple following after when referring to the future:
I’ll contact you after we reach the airport.
After or afterwards as an adverb
We can use after as an adverb, but afterwards is more common. When after is used, it is usually as part of an adverb phrase:
They lived happily ever after. (means ‘for ever’)
She had an operation on her leg and afterwards was unable to walk for at least a month.
After: typical error
When after refers to future time, we use the present simple, not the future with shall or will:
I’ll do another course after I finish this one.
after I will finish…