Test preparation

• Arihant Problem Book in Mathematics for IIT JEE by SK Goyal
• NCERT Maths Class 11 and 12
• Cengage Maths by G TIWANI
• Comprehensive Mathematics for JEE Advanced by Tata McGraw Hill publications
• Problems Plus in IIT Mathematics by A Das Gupta

You begin ACT preparation by checking the syllabus, solving practice tests, and learning timing tricks. Start slow and then do more tests later. Following this can help one in getting a desired score.

The past perfect tense can be used in four forms:

• Affirmative: Subject + had + past participle of verb + object.
• Negative: Subject + had + not + past participle of verb + object.
• Interrogative: Had + subject + past participle of verb + object.
• Negative + Interrogative: Had + subject + not + past participle of verb + object.

Have a look at the examples of the past perfect tense below:

• The movie had already started when we arrived at the theatre.
• The teacher had scolded him as he misbehaved.
• Had the movie begun already?
• Had he not finished playing football before dinner?
• Sheetal had gone to the market when the incident happened.

As per the English Grammar rule for Past Perfect tense, the sentences in this verb form are formed using had with past particple (ed) of the verb. The Past Perfect tense rule or formula is:

Subject + Had + Past Participle of Verb + Object 

Past Perfect tense in English grammar is used to describe an action that was completed before another action in the past. The sentences in Past Perfect tense are formed using had + past participle (ed). Have a look at a few Past Perfect Tense examples below:

·       The path is broken as it had rained all night yesterday.

·       Had the Police arrived on time the robbery could be prevented?

·       She had left early yesterday because of the event.

Yes, 'United Nations' can be considered as a collective noun. It represents a group of countries working together for global issues like human rights, health, peace, etc. The United Nations is made up of many members, but is treated as one organization, making it a collective noun.

Example:

• The United Nations has declared a new healthcare policy.
• The United Nations is working to stop climate change.

Yes, 'police' is a collective noun. It represents a body of officers acting together. Additionally, unlike many other English collective nouns, 'police' is always used with a plural verb. Simply put, instead of saying 'police is', we say 'police are'.

For example: 

• The police have arrested the thief.
• The police are patroling on the streets of New York.

Collective nouns for animals are the English words used to name a group of the same species. For instance, instead of saying 'many lions' we say 'a pride of lions'. Similarly, there are unique names for different groups of animals. 

Collective Nouns of Animals Examples

• A murder of crows
• A gaggle of geese
• A school of fish
• A flock of birds
• a tower of giraffes
• A drove of horses
• A nest of mice

No, collective nouns are not just restricted to objects. According to Oxford Dictionary collective noun is, “a singular noun, such as committee or team, that refers to a group of people, animals or things. 

Here are some collective nouns examples for reference.