Scribblers Retreat

I run an ESL program at church. I usually have the intermediates these days, but some weeks, when my students have to work, I help out with the advanced class, since the teacher there isn't a native. I get peppered with questions on the nuances of language.

Last night: What's the difference between "I doubt" and "I'm not sure?" At first, they seem like synonyms. As I gave it a quick thought, though, I realized I don't use them interchangably.

Example:
"You're having trouble with your car. Let me fix it for you."
"You're a great mechanic, but I'm not sure you can fix this one. Do you have experience with antique cars?"

""You're having trouble with your car. Let me fix it for you."
"Ummm...you're ten years old. I doubt you can fix my car."

Tone of voice for the first is politer than for the second, where a bit of sarcasm is blended in.

I'm beginning to think more about the nuances of our language as I answer these types of questions. The difference between an average writer and a great one might be, in part, an ear for nuance.