помогите правильно поставить артикль а/an в словосочетаниях playing boy.running...

Question

помогите правильно поставить артикль а/an в словосочетаниях playing boy.running sportsman.opened book.singing girl.flying bird.built house.eaten breakfast.sent lette.falling chair.decorates room.

Answer 1

a playing boy 

a running sportsman

an opened book

a singing girl

a flying bird

a built house

an eaten breakfast

a sent letter

a falling chair

a decorated room

Answer 2

a, a, an, a, a, a, an, a, a, a