Gwen Mak
Should have learned...
Wish I had learned... Could have, would have, should have...
We've all heard and said those phrases many times. However, we've also heard (and maybe said) them incorrectly. As a self-professed grammar nerd, it makes me cringe when I hear or read intelligent people using incorrect grammar. You're obviously an intelligent individual (I mean, you've made it to this website, right?) have you ever questioned the etymology of a word or wondered if you're saying or using a common phrase incorrectly? In this series, I'll be writing about some of the common grammar faux pas I encounter and how to fix up your speech and writing to Sound Smarter, and elevate your speech to the level of your intellect.
First things first, we'll begin with the modals with which I started this post.

These words are modals, which paired with the verb have describe something which potentially happened. There are two ways I have heard these words used incorrectly.
Substitution
People say 'should of' instead of 'should have.' The phrase 'should have' is commonly heard in its contracted form, 'should've' which sounds very close to 'should of' so I suspect that's the cause for confusion.
Past Participle
These modals should be followed by the past participle, not the simple past tense. Because sentences using these words indicate that an action may or may not have happened, we have a different verb tense to match the potential quality of the action. For example, when I'm sure that I ate a slice of cake, I can say, "I ate that cake." If I also know I am on a diet, I might follow up with, "I should not have eaten that cake" as opposed to "I should not have ate that cake."
Common simple past and past participle mistakes: