You can reform your tongue! Start by pattering your conversation after Jesus.
Jesus spoke gracious words:
And all bare Him witness, and wondered at the gracious words which proceeded out of His mouth, And they said, Is not this Joseph's son? (Luke 4:22)
Jesus spoke words of authority:
And they were astonished at His doctrine: for He taught them as one that had authority and not as the scribes. (Mark 1:22)
There was no guile (sinful speaking) found in His mouth:
Who did no sin, neither was guile found in His mouth; Who, when He was reviled, reviled not again; when He suffered, He threatened not; but committed Himself to him that judgeth righteously. (1 Peter 2:22-23)
You can choose to speak:
Words of wisdom:
My mouth shall speak of wisdom; and the meditation of my heart shall be of understanding. (Psalms 49:3)
Words that describe God’s works instead of worldly concerns:
I will speak of the glorious honor of thy majesty, and of thy wondrous works. (Psalms 145:5)
Words about God’s Word. Talk about what you are learning and what the Word is doing in your life:
My tongue shall speak of thy Word; for all thy commandments are righteousness. (Psalms 119:172)
Words of comfort:
Wherefore comfort one another with these words. (1 Thessalonians 4:18)
Words about the Kingdom of God:
They shall speak of the glory of thy Kingdom, and talk of thy power. (Psalms 145:11)