Question

I can’t think _________ the name but it’s ________ the tip of my tongue.
Fill in the blanks with suitable prepositions
A) on/on
B) about/at
C) of/on
D) of/at

Answer 1

Hint: A word or group of words used before a noun, pronoun, or noun phrase to show direction, time, place, location, spatial relationships, or to introduce an object is called a preposition.

Prepositions are the words that tell about
- the relationship between the words in a sentence
- time of happening of an event
- Place of happening of an event

Complete answer:
Let us understand the use of the prepositions given in the options-
I) On - It is used to tell the position. For e.g. Cat is sitting on the wall. Or, it tells about specific times(days,dates) For e.g. I bought it on my birthday.
II) About - It indicates the ‘noun’ we are referring to, it also means ‘approximately. For e.g. I read an essay about Mahatma Gandhi or I am about to reach the party.
III) At - This can indicate a specific place, a particular time, or a specific activity. It is also used with email addresses. For e.g. Meet me at 8:00 pm tomorrow.
IV) Of - This tells about the ownership (e.g. the owner of this dog lives there), something we relate to (e.g. she told me a story of an old lady.), while referring to something (e.g. this reminds me of our last trip.), to tell about a specific quantity or number (e.g. I bought 10 packets of chips.)

The correct answer is of/on. The complete sentence will be , ‘ I can't think of the name, but it is on my lips.’ ‘Of’ in the sentence is used to refer to the name thus, when we are ‘referring to something’ we can use of. Similarly ‘on’ tells about position like in the sentence it tells ‘ on the lips’.

Therefore the correct answer is option ‘C’.

Note: There are many words which act as an adverb as well as a preposition. Therefore, to identify, when a word is functioning as a preposition, we must remember that the sentence with preposition has an object which comes after the preposition.