My mother-in-law asked me to pick up green onions from the store. When I got home, she said I’d bought scallions instead and refused to use them. She was pretty rude about it. I honestly thought they were the same thing—are they actually different, or just different names for the same thing

Short answer: You were basically right. In everyday use, green onions and scallions are the same thing or close enough that most people—and many grocery stores—use the names interchangeably.

Scallions / Green Onions

• These are young onions harvested before the bulb fully develops.

• They have long green stalks and a small white base.

• The flavor is mild and slightly sweet.

• Both the white and green parts are edible.

• In many recipes and stores, they’re simply called green onions.

Where the Confusion Comes From

Sometimes people mix them up with spring onions:

• Spring onions are a bit more mature.

• They have a small round bulb at the bottom.

• Their flavor is stronger than scallions.

The Bottom Line

For most cooking purposes:

• Green onions = scallions (same thing in most places).

• Spring onions are slightly different but still very similar and often used the same way.

So it’s very understandable that you thought they were the same—many cooks and grocery stores treat them as identical.