Grammar Rules

Question 1

When we introduce the name of a Nation with the article “The”?

Answer 1

In 2 cases:

. When the name of the Nation includes a reference to the government structure of the Country. E.g. The Dominican Republic, The U.S.A.

. When the name of the Nation is plural e.g. The Philippines

Question 2

Past perfect tense:

. How to form it?

. When we use it?

Answer 2

Past perfect tense:

. How to form it? > had + past participle (had done or had left or had played)

. When we use it? > The past perfect takes place before another past action

I noticed (some point in the past) that he had left (some point more in the past) his books behind

Question 3

Why year is singular in the first sentence and plural in the second?
A 16-year-old girl
She is 16 years old

Answer 3

In the first sentence year is an adjective jointly with the words 16 and old (this is why we use the hyphen). Adjective are always singular, they don’t change according to the name

In the second example years is a noun and 16 is the adjective