Back when I talked about bullet points, one of the tips involved keeping each bullet item in parallel by beginning with the same part of speech. For example, each item might similarly begin with a verb like so:

deliver, prompt, cause, drive

When writing a list of items in paragraph form, this is even more crucial, and failing to stay in parallel can result in confusion for readers and scorn from English majors. Check out this non-parallel list in a sentence:

Over the weekend, Kevin bought a new MacBook Pro online, two software programs, and arranged for free shipping. Do you see the problem? If not, break the list into bullet points and it becomes clear:

Over the weekend, Kevin:

    Bought a new MacBook Pro online
    Two software programs
    Arranged for free shipping

Stick the word “ordered” in front of “two software programs” and you’re in parallel. Your readers will subconsciously thank you, and the Grammar Nazis won’t slam you.