There are many synonyms for the phrase 'uses bad language'. Some of these include swearing, cursing, cussing, foul language, expletives, profanity, obscenities, and vulgarities. While the use of such language may be common in some social circles or situations, it is generally seen as impolite and offensive. Using bad language may also be considered unprofessional or inappropriate in the workplace or other formal settings. It is important to be aware of the tone and language used in communication to avoid offending others. A wider vocabulary that is free of bad language can be used to express oneself in a more articulate and respectful manner.