•below and under
•‘Below’ and ‘under’ can mean 'lower than' and sometimes either can be used. But ‘under’ can indicate contact:
•She put the letter under her pillow.
•The ice crackled under his feet.

With ‘below’ there is usually a space between the two surfaces:
üThey live below us. (We live on the fourth floor and they live on the third.)
•‘under’ can mean "junior in rank'.
üHe is under me.

‘below’ does not necessarily have this meaning.

But we can use ‘below the rank of ……..’

Officers below the rank of captain receive no special previleges.
üThe pole is below the building. (not directly under)
üThe banana is under the hat. (directly under)



below (preposition and adverb) and under (preposition)
üThe lake is almost 800 feet below sea level. (below = preposition)
üI heard someone calling from the street below. (below = adverb)
üFor further information see below.
üHe went below to speak to the manager.



not directly under: below

We prefer ‘below’ when one thing is not directly under another.
üThe climbers stopped 300m below the top of the mountain.

There is a cave right under the mountain. (directly under…)
üShe was standing below the apartment.

There is a basement under the apartment. (directly under…)
•

covered: under

We prefer ‘under’ when something is covered or hidden by what is over it, and when things are touching.
üI think the cat's under the bed.
üWhat are you wearing under your sweater?
üThe whole village is under water. (NOT... below water)

measurements: below

‘Below’ is used in measurements of temperature and height, and in other cases where we think of a vertical scale.
üThe temperature is three degrees below zero.
üParts of Holland are below sea level.
üThe plane came down below the clouds.

'less than': under

We usually use ‘under’, to mean 'less than' or 'younger than'.
•There were under twenty people at the lecture.
•You can't see this film if you're under 18.

‘below’ means ‘less than’ when we talk about numbers in a scale:
•The temperature is below 10.
•Your performance is below average.

underneath

‘Underneath’ and ‘under’ are same. It can be used as a preposition instead of ‘under’, but only for physical position.

Compare:
•There's a mouse under/ underneath the piano.

But while measuring something these are not the same.
•He's still under 18. (NOT …underneath 18)



beneath

‘Beneath’ means ‘below’
•The children are playing below/beneath my apartment.
•The drawer are below/beneath the mirror on the wall.



Differneces:

‘Beneath’ is always followed by an object (noun/pronoun) but ‘below’ need not one.
üI can hear voices below.

‘Beneath’ is common before abstract nouns in some fixed expressions.
•He acts as if I was beneath his notice. (= not worth considering)
•Her behaviour is beneath contempt. (= really disgraceful)

‘Beneath’ cannot be used in a scale:
üYou score is below average.

‘Beneath’ can have the meaning of ‘inferior’ or ‘unworthy’ but below does not.
üThe job of making coffee is beneath me. (inferior to my status)
üShe married a boy beneath her. (inferior social status)