Bring a pot with 4 quarts (4 L) of water to a boil for the linguine.
Meanwhile heat the oil in a heavy 3-quart saucepan. Add the garlic, cook for a minute, then stir in the broccoli rabe. When the rabe has wilted, stir in the clams, cover, and cook over low heat until they have opened, about 10 minutes.
When the water for the linguine is boiling add the pasta, stir it, and cook until it is al dente, about 8 minutes.
Drain the pasta, reserving about 2 cups (500 ml) of the cooking water, and return the pasta to the pot.
Stir about a cup (250 ml) of the pasta cooking liquid in with the clams, then transfer the clams and broccoli rabe to the pot with the linguine.
Mix the ingredients well.
Add more liquid from the linguine if necessary.
Sprinkle with hot red pepper flakes and serve.