Articles like 'a' and 'an' are only used with Singulars
They are not used with plurals
This is a tree
(It is one tree so we use "a")
These are trees
(There are more than one trees, so we do not use "a")
He is ... thief.View Answer
He is a thief.
It is one thief so we use " a "
They ... thievesView Answer
They are thieves
They are more than one thieves, so we do not use " a "
She is ... honest girlView Answer
She is an honest girl
She is one girl so we use " an "
They ... honest girlsView Answer
They are honest girls
They are more than one girls, so we do not use "an"