I saw this in an email message.

Problem:
A comma is missing.

Explanation:
Without the comma, this sentence is structured such that the writer is thanking the reader for sharing Jim.

What the writer wanted to do was thank Jim for sharing (the information contained elsewhere in the email message).

Commas provide the pauses that let readers “hear” where writers are taking breaks in speech.

The writer of the sentence in the email message was pausing before saying in her mind the name Jim, but she failed to put in her sentence a comma that would indicate the location of that pause.

Solution:
“Thanks so much for sharing, Jim.”

I instant-messaged someone whom I’ll call Kathy while talking with her in a conference call.

I wrote, “I asked, Kathy, about the session sheets because …”

She replied, “…who did you send this to?”

After some confusing back-and-forth, I realized that Kathy did not see the commas in what I initially wrote.

She thought that I wrote, “I asked Kathy about the session sheets because …” That would have been a third-person reference to Kathy. She thought that I had instant-messaged someone else with “I asked Kathy about the session sheets because …” before instant-messaging the same thing to her.

Instead, because I wrote, “I asked, Kathy, about the session sheets because …”, I was referring to her in the first person. I was trying to make my instant message more personal by pausing (with commas) to include her name.

Lessons:
1. Commas can change a third-person reference to a first-person reference.
2. Don’t assume that readers will see your commas, especially in an instant-messaging situation.
3. Don’t assume that a reader who sees your commas will know that these are equivalent to pauses in the spoken version of what you write. If a reader can’t “hear” the pauses implied by the commas, then the reader will read a first-person reference as a third-person reference.