Tone Tips, Part 12: Avoiding "I Can't"

Here's an easy one—so easy that I'm surprised how few people practice this principle. For the sake of good tone, avoid placing side by side I and can't. (The same applies to we can't or the company can't.) Especially if you are in a service business, the point of your job is to tell your readers what you can do, not 
what you can't do. 

In the examples that follow, the first draft seems defensive, dismissive, or accusatory, while the second draft appears positive, committed, or considerate.

Draft 1: I can't help you until you pay me.
Draft 2: I can help you when you pay me. 

Draft 1: We can't process your application since you did not complete the form.
Draft 2: We can process your application once you complete the form.

Draft 1: The company cannot finish the work because the client did not supply the materials.
Draft 2: The company will finish the work upon receipt of the materials.

At times, we may have no choice but to use a negative construction. For instance, we might have to write we can't when a customer insists on the assistance without the prerequisite after we have already used the positive expression. But we should make I can our default.