Marinated and Grilled Zucchini and Summer Squash

Heat grill to medium. In a large bowl, gently toss zucchini, squash, oil, vinegar, and oregano; season with salt and pepper. Working in batches if necessary, lift vegetables from marinade, and grill, covered, turning once, until tender, 6 to 8 minutes. Reserve marinade. (To store, refrigerate vegetables and remaining marinade separately, up to 1 day.) Drizzle grilled vegetables with remaining marinade, and serve.