Choose the correct article for the sentence:  

Copper is ____ useful metal.

a

In English grammar, articles are words that define a noun as specific or unspecific. There are three articles in English: 'a', 'an', and 'the'.

1. Indefinite Articles ('a' and 'an'):

   • 'A' is used before words that begin with a consonant sound.
   • 'An' is used before words that begin with a vowel sound (a, e, i, o, u).

   Both 'a' and 'an' are indefinite articles, meaning they refer to a non-specific item or thing. For example:

   • "I saw a dog." (Could be any dog, not a specific one.)
   • "She ate an apple." (Could be any apple.)
2. Definite Article ('the'):
   • 'The' is used to refer to a specific or particular item, person, or thing that both the speaker and listener are aware of.
     For example:
   • "I met the teacher you were talking about."

Why is "A" the Correct Choice?

Now, looking at the sentence, "Copper is ____ useful metal," we need to choose the correct article:

• The word 'useful' begins with a vowel letter 'u', but we must pay attention to its sound when choosing between 'a' and 'an'.
• The sound of 'useful' starts with a y sound, which is a consonant sound (pronounced like "yoo-sfull").
• Therefore, since 'useful' begins with a consonant sound, the appropriate article is 'a', making "A useful metal" the grammatically correct choice.