The semicolon is primarily used to join independent clauses (i.e. complete sentences) that are closely related and are not joined with a coordinating conjunction (i.e. and, or, not, for, yet, but, and so). Semicolons can also be used to separate phrases in a list but only when those phrases contain internal punctuation.
Find me a woman with a pug; I’ll find you a lucky lady.
But remember if you use a coordinating conjunction [and, but, yet, nor, or, if, and so] then you only need a comma.
Find me a woman with a pug, and I’ll find you a lucky lady.
Note: many independent clauses begin with “transitional expressions,” such as: accordingly, also, besides, certainly, conversely, finally, furthermore, however, indeed, instead, meanwhile, nevertheless, otherwise, similarly, subsequently, then, therefore, thus, or with “transitional phrases,” such as: after all, for example, in addition, in conclusion, in fact, on the contrary, on the other hand.
When joining independent clauses, you need a semicolon before the transitional expression or phase and a comma after it.
Pets are important to good health; in fact, studies have shown that people who have pets have lower blood pressure.
When listing phrases with internal punctuation, the semicolon provides clarity.
Most breeds of dogs have distinctive features such as pugs, with their large, soulful eyes; terriers, with their jaunty walk; and golden retrievers, with their glossy coats.