I bought a camera and a microphone, butdidn39;t work. the microphone

I bought a camera and a microphone, but the microphone didnt work.

There are two articles in English. They are definite article and indefinite article. The indefinite article is a / an. The meaning of the indefinite article is one. The difference between them is a is written before consonants (a microphone) and an is written before vowels (an egg).

The is the definite article. It is used when the object is already known. I bought a microphone. And this one (the microphone) that I bought didnt work. We have already known which microphone is spoken about.