Naipathika Wakyansha - නෛපාතික වාක්‍යාංශ - Prepositional Phrases. 

Besides prepositions which are single words, there are others consisting of two or more words. These are called Prepositional Phrases, and there are many of them which are in constant use.

Examples.

I did it for the sake of the children.

Take this stick instead of an umbrella.

We bought this car with a view to selling it someday.

We could not go to Anuradhapura on account of the heavy rain.

With regard to that matter, I will let you know later on.

I got the ball from the roof by means of a ladder.

The price varies according to the quality.