When we open our mouths, how are we suppose to talk? How can we measure our speech - written or verbal?
Proverbs (16:4) tells us what is the Right Way To Talk:
"A soothing tongue is a tree of life, but it's harshness damages the spirit"
This means that when we talk, we should aim to HEAL with our tongue which is the greatest healer of all medicine. And the opposite is true also: the tongue can cause a lot of damage and make others sick.
No wonder the same person (Shlomoh Ha Melech) said
"Mavet Vechayim Beyad Halashone", if you "cannot do it" then, Silence is golden!
The test of speech is simple: Are you healing someone with your words or just making them sick?