29 Do not let any unwholesome talk come out of your mouths, but only what is helpful for building others up according to their needs, that it may benefit those who listen.

Read Ephesians 4:29 Using Other Translations

Let no corrupt communication proceed out of your mouth, but that which is good to the use of edifying, that it may minister grace unto the hearers.
Let no corrupting talk come out of your mouths, but only such as is good for building up, as fits the occasion, that it may give grace to those who hear.
Don’t use foul or abusive language. Let everything you say be good and helpful, so that your words will be an encouragement to those who hear them.