Question

Put in a/an or some, where necessary. If no word is necessary, leave the space empty (-).

________ birds, such as the penguin, cannot fly.
(a)some
(b)a
(c)an
(d)(-)

Answer 1

Hint: Indefinite articles are usually used before a noun that is general or when its identity is not known. Definite articles are used when the identity is certain, however not before a proper noun with some exceptions.

Complete answer: Indefinite articles are used for a thing or person when
the reader doesn’t know which one we are referring to out of many nouns. It is used for
denoting the random nature of an object.
‘The’ is used as a definite article for a thing or person when the reader knows which one we are exactly referring to. It states the specific nature of the subject. The word ‘birds’ is not a proper noun. So, it is inferred that it is a common noun. However, there will still be no article before it, as it is a plural common noun.

We use some before nouns to refer to indefinite quantities. Although the quantity is not important or not defined, using some implies a limited quantity. This is exactly what we need.
Now, we know what we are looking for. Let’s look at the given options:
(a)some - The word ‘some’ is used as a determiner. It is the required answer, as it indicates the specificity of the noun. This is the required answer. So, this is the correct option.
(b)a - The article ‘a’ is an indefinite article. It is used more in a general sense, however, these also cannot be used before a plural common noun. The word following the blank is ‘birds’ which is a plural common noun. This is not the required answer. So, this is an incorrect option.
(c)an - The article ‘an’ is an indefinite article. It is used more in a general sense, only before words beginning with a vowel, however, these also cannot be used before a plural common noun. The word following the blank is ‘birds’ which is a plural common noun. This is not the required answer. So, this is an incorrect option.
(d)(-) - The noun given in the sentence is a common noun which is plural. But it requires specificity. This does not fit perfectly into the given sentence, as we require a determiner. This is not the required answer. So, this is an incorrect option.

Note: To choose the correct indefinite or definite article, pronounce the word after it. If it is a vowel sound, there will be only one correct option. That will be the correct answer for the given sentence. However, there can also be no article used, and the word ‘some’ will be used.