A preposition is a word used to link nouns, pronouns, or phrases to other words within a sentence. Prepositions are usually short words, and they are normally placed directly in front of nouns. In some cases, you’ll find prepositions in front of gerund verbs.
\(1\). to refer to two things which are clearly separated
\(2\). when naming individual items (\(2,3\), or more)
Our house is between the mountains and the sea.
Switzerland lies between France, Germany, Austria and Italy.
|among||when the items are part of a group||I’m trying to decide among these shirts.|
|before||earlier than a certain point of time||Can you call me back before 5 pm, please?|
|behind||at the back of somebody/something||The teacher was standing behind me.|
period of time
(within the period)
|Nobody spoke during the presentation.|
\(1\). reason or purpose
\(2\). length of time (how long the
This gift is for you.
It rained during the night for two hours.
|with||together||He was with his friend when he saw me.|