If the clauses of a compound sentence are equivalent, you may use a semicolon instead of a comma and a conjunction between them:

My father’s father talks to strangers; my mother’s mother does too.

However, if you want to show a relationship between different clauses, use a comma and a conjunction:

I’m talkative, too, so this tendency may be a family trait that skips a generation.

If the sentence is very long, consider making each clause a separate sentence.

Semicolons can also impose order on unruly series. If one or more of the elements in a series contains a comma, use semicolons to separate the elements:

My father grew up in Mumbai, India; my mother grew up in Delhi; and my brothers and I grew up here.

In her garden, my grandmother grows magnolias, ylang ylang, and lilies because she loves their scent; orchids because they are beautiful; and mangoes, pineapples, and bananas because she loves to eat them.