There are several different species of spam email out there.
Some of it is just plain gibberish, often just a few random words and a link. This kind is pretty easy to spot.
There’s also the kind you get because you actually signed up for it. In this case, it’s not actually spam, since you opted in. Most of the time, this form of commercial email message (usually from larger, well-established companies) is relatively safe. There’s usually a link at the bottom you can follow if you want to stop receiving these messages.
Then there’s the stuff that tries to look like it’s from a legitimate business. Usually this sort of message has quite a bit of text, and many times it’s written with passable English grammar and spelling. It can be selling a reasonable-sounding product, but the difference is that it’s from a company you’ve never done business with, and from whom you did not sign up to receive email. There will usually be an “unsubscribe” link at the bottom of the message as well.
However, in this case, you do not want to click that link. When you do, it takes you to a website that asks you to enter your email address to take yourself off the list. What you’re actually doing is confirming that the email address they have on file is a good one. Basically, your address can then be sold to any number of spammers. It will only cause more spam (and scams) to appear in your inbox.
The only way to deal with this kind of spam is to ignore it. It’s a pain, but it’s a bigger pain if it multiplies (I learned that one the hard way several years ago). Either adjust the settings on your spam filter, or just manually delete the messages every time.