Language/English/Vocabulary/Along

Along

The preposition along is used before nouns like road, river, corridor, line: words that refer to things with a long thin shape. 

Examples:

I saw her running along the road.

His office is along the corridor.  

To talk about periods or activities, it is better to use "through". 

Examples:

Through the centuries (not along the centuries)

Right through the meal

All through the journey (not along the journey) 

There is the special use of "along" as an adverb particle in expressions like:

Come along (= Come with me) or walking along (= walking on one’s way).