Key difference: 'Of' connects words. It does not actually have a meaning. It is a preposition, and hence it is used to denote a relationship. It just connects words, without actually modifying the meaning. ‘Off’ on the other hand has a proper meaning. In fact, it has various meaning. However, generally it can be considered the opposite of ‘on’. ‘The light is on’; ‘The light is off’. ‘Off’ is very versatile, it can be used as an adverb, a preposition, an adjective and a noun.

The words ‘of’ and ‘off’ look very similar to each other; in fact, until the 17^th century, both used to be the same word. However, in today’s common English, the words have two distinct uses. Just a single ‘f’ can change the entire meaning on the sentence.

The word ‘of’ can fulfill several difference functions in a sentence. It can be used to indicate:

• belonging to somebody/something (a member of the team)
• coming from a particular background (the people of Wales)
• to indicate what something contains (a glass of milk)
• a point of reckoning (South of the border)
• construction (Heart of gold)
• possession (Queen of England)

'Of' connects words. It does not actually have a meaning. It is a preposition, and hence it is used to denote a relationship. It just connects words, without actually modifying the meaning.

‘Off’ on the other hand has a proper meaning. In fact, it has various meaning. However, generally it can be considered the opposite of ‘on’. ‘The light is on’; ‘The light is off’. ‘Off’ is very versatile, it can be used as an adverb, a preposition, an adjective and a noun. It can be used in various methods, such as:

• to denote a location (An island off the coast of Spain)
• to describe a situation (She is better off without him.)
• to describe something (The milk smells off.)
• when speaking of machinery (The air conditioning is off.)
• when someone leaves (He is off for the day.)
• and many more…

Further examples of ‘of’:

• I am spreading the top layer of icing on to the cake.
• The manager is a representative of the office leadership.
• Wash your hands of everything.
• John is a man of good family.
• I think I’m dying of hunger.
• Mary has a book of poems.
• Is that idiot of a salesman calling again?
• I’m going to visit the city of love.
• Rupert is one of us.
• There is talk of peace.
• I need three kilos of sugar.
• She was born on the 21st of July in New York.
• There were a lot of people standing in line.
• We're going to reach the top of the hill.
• They live in a block of flats on this street.

Further examples of ‘off’:

• This button is about to come off.
• Take off your hat.
• Turn off the light.
• Take it off the table.
• The gas station is just off the corner ahead.
• The pudding takes a bit off.
• I am scraping the top layer of icing off of the cake.
• The manager is off to a meeting in Chicago.
• Wipe the sweat off your face.
• Take the wrapping off the gift.
• This road branches off to Grove City.
• He took 10% off for all cash purchases.
• Everything was 50% off.
• The alarm goes off at noon.
• My headache passed off soon.
• Mark the pizza off into equal parts.

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