The word main describes something that is the most important, like the main event or the main idea. A mane is the long hair growing on the head and neck of some animals, like horses and lions.

Main Street is usually the principal road in a city or town, or at least it was when the town was first established. A main clause in a sentence includes the most important idea, and it can stand on its own as a complete thought. A story always has a main character, like Dorothy in The Wizard of Oz. As a noun, a main is a principal pipe or wire in a utility system. For instance, a water main may run under the middle of the street carrying water to all the neighborhood buildings. The following sentences illustrate correct uses of main:

She zipped us off the main road and down a few steep side streets. (We Were Here)

The main idea of the law is to regulate AI based on its capacity to cause harm to society. (BBC)

The city says a water main broke Tuesday, causing the pressure drop. (The Washington Times)

The mane around a male African lion's head is one of the most famous manes on the planet. In a way, a lion's mane looks a bit like a crown; perhaps that's why the lion has often been portrayed in stories as the "king of the jungle." (The roar helps, too!) A horse has a very different mane that falls all along its neck. Some riders braid their horse's mane or grab on to it to help hold on when galloping! Other animals with manes include zebras, giraffes, buffalo, and hyenas. Sometimes, a person's thick, flowing head of hair is also referred to as a mane. Here are a few examples of mane in sentences:

He was the most powerful lion that the woman had ever seen, and she wailed in fright at the sight of his great shoulders and the shock of golden mane that framed his face. (The Girl Who Married a Lion)

The horse munched on the apple in her palm as Ava ran her other hand along its mane. (The Washington Post)

You can use the i in main to remind yourself that main applies to something that is the most important. And you can use the "man" in mane to remember that even a human can have a mane.