When a comma is like a choo-choo train

I help my clients with writing tips. Here's one on commas:

When's the right time to use a comma in a series, and more importantly, when do you — not? Think of a series of items in a sentence like a freight train.

In a train, the first car is the engine. It pulls the entire train, is usually the most powerful car on the train and sets the tone for the experience. The caboose brings up the rear of the train. The caboose is usually red and well-lit to signal the end of the train, houses the employees during a journey and, most importantly, signifies this is a train long enough to warrant a caboose.

All the cars between the engine and the caboose mean money for the train, whether they're carrying people, milk, petroleum or lumber. The more cars, the more money. If the only car behind the engine is the caboose, the train is making no money.

So.

Put a comma between every train car in your series. Every single one except the one before the caboose. Cabooses can't stand commas. The very thought of them turns them red. Use and instead of a comma.

Imagine reading a series aloud: The commas tell you, hey, another car's on the way.

"I’ll have one hot dog, one milkshake, one hamburger and french fries."
"You’ll have nothing and like it."

Here's another kind of train, this one for semi-colons. On this train, the cars themselves are filled with different items, so you save the commas for inside the train cars and semi-colons for between the train cars.

"My dream vacation would be going to Las Vegas, for gambling and pool-hopping; New York, for clubbing and baseball; and Paris, for the women, wine and museums. Now if I could only take a train ..."

Lastly, place a semi-colon and and before a caboose. That's right; in a series with semi-colons, the and goes inside the caboose.