I am a sensoral thinker, I often think and internally express myself in purely images or sounds. There are, however, some kinds of thoughts I've learned I can only fully engage with if I speak to myself out loud or at least inside of my head.
The most appropriate mode of thought depends upon the task at hand. People don't typically brag about having internal monologues. They're just sharing their own subjective internal experience, which is no less valid than a chiefly nonverbal one.