Bring a large pot of salted water to a boil. Cook the spaghetti or linguine according to package instructions until al dente. Drain and set aside, reserving 1/2 cup of pasta water.
While the pasta cooks, season the shrimp with salt and pepper.
In a large skillet, melt 2 tablespoons of butter over medium-high heat. Add the shrimp and cook for 2-3 minutes per side until pink and opaque. Remove the shrimp to a plate and set aside.
Pour in the white wine or chicken broth and lemon juice. Simmer for 2-3 minutes, allowing the liquid to reduce slightly.
Return the shrimp to the skillet along with the cooked pasta. Toss everything together, adding a splash of reserved pasta water if needed to loosen the sauce.
Stir in the chopped parsley and adjust seasoning with salt and pepper to taste.
Serve hot, garnished with grated Parmesan cheese if desired. Enjoy your garlic butter shrimp pasta!