Simplify the following text for a Grade 7 native English-speaking person.
Original: The islands of Saint Vincent and the Grenadines include the main island of Saint Vincent ( 344 k ) and the northern two-thirds of the Grenadines ( 45 k ) , which are a chain of small islands stretching south from Saint Vincent to Grenada .
Simplified: Saint Vincent is the largest island , and the Grenadines are a group of smaller islands .