Bring a large pot of lightly salted water to a boil. Add corn and haricots verts; cook for 2 minutes. Remove with a slotted spoon to a large bowl.
Return water to a boil and add linguine. Cook for 12 minutes or as per package directions. Drain, reserving ½ cup of the pasta water.
Meanwhile, heat 3 tbsp of the olive oil in a large skillet over medium heat. Cut corn kernels from cobs and set aside. Add tomatoes, sweet pepper, garlic and scallions to skillet. Cook, stirring, for 3 minutes.
In a large bowl, toss pasta with remaining 1 tbsp olive oil. Add tomato mixture, corn, haricots verts, lemon juice, parsley, salt and pepper. Gently toss and add some of the reserved pasta water if too dry. Stir in Parmesan to taste. Serve warm.