Have you ever wondered why contestants in the television game show Wheel of Fortune are given the letters R, S, T, L, N, and E? The show wants to get straight to business, so they give away the most common letters.
You'll find that many adjectives that start with "r" begin with "re-." You can add the prefix "re-" to so many words. It often means "again," as in your favorite food is refried beans, your failed test is redoable, or your old car is fully restored. That said, "re-" doesn't always mean again, it can also mean "back" or "behind." You might be reluctant to ride your bike at night without reflective gear.
So, "r" is a multi-faceted letter of the alphabet, and it will be helpful when building your own List of Common Adjective Words. After spending some time, you'll have rather a robust list on your hands. So, let's get started.