Is your conversation such as to bring glory to God. Can people tell you are Christian by the language that you use? Do you talk like a sailor? Do you tell dirty jokes? Do you laugh when others do?
Are the effects of your words such as to build up the kingdom of God?
Say this prayer daily and with meaning:
Let the words of my mouth, and the meditation of my heart, be acceptable in thy sight, O Lord, my strength, and my redeemer.
(Psalm 19:14)