I guess that using language responsibly would mean that you pay attention to the meaning of words, and don't use them inappropriately. You pay attention to spelling and grammar and give your best effort in making both correct (without overdoing it and obsessing). You try to be exact with your words rather than muddying the meanings in order to skew perspective. You set an example for others by using words correctly and incorporating proper pronunciation. You vary the words you use for emphasis so that you don't overuse the same exclamations. You are creative and find ways to build vocabulary and use new words in your everyday interaction. You appreciate language and use it as a tool, or an art form... not a bludgeon.