What is the difference between professional and casual communication styles?

The difference between professional and casual communication styles is the professional communication style is expected to be formal while the casual is informal. Professional communication styles are usually used when writing school papers and in correspondence between co-workers and with clients. Casual communication styles are used when writing notes or letters to friends, in text messages, and or social media.

The CORRECT answers are: lose 2, gain1, lose1, not form an ion, lose 3