A - AN

1. Article "A"

1.1. 1- a window

1.2. 2- a university

1.3. 3- a horse

1.4. 4- a lamp

2. Article "AN"

2.1. 1- an orage

2.2. 2- an elephant

2.3. 3- an igloo

2.4. 4- an airoport