Along can be used as a preposition and an adverb. When used as a preposition, it is followed by a noun. When used as an adverb, it is not followed by a noun.
- The boys walked along the corridor. (Here the noun the corridor acts as the object of the preposition along.)
- You can bring your kids along.
Along is used to talk about movement on or beside a line.
- She walked along the footpath.
- I saw a dark figure moving along the road.
Along can also show position on a line.
- There are quite a few shops along the street.
- There was a thick line of trees along the river bank.
Along can be used to talk about coming or going to a place where someone is waiting or something is happening.
Although we waited for hours, no cabs came along so we decided to walk all the way home.
- We are going to the theatre. Would you like to come along?
To take someone or something along is to take them with you when you go somewhere.
- Don’t forget to take these papers along when you go to the bank.
Note that the preposition along is not used to talk about periods or activities. Instead we use through.
- She was silent all through the journey. (NOT She was silent all along the journey.)
- She kept talking right through the meal.