Common Mistake: Comma before 'so/but/and MD + PRP + VB'

Using a comma before the combination of 'so/but/and', followed by a modal verb (MD), a personal pronoun (PRP), and a verb (VB) is a common punctuation mistake.

Let's take a look at the correct usage:

• Incorrect: I wanted to go to the party, so I can see my friends.
• Correct: I wanted to go to the party so I could see my friends.

In the incorrect example, a comma is used after "party" before the conjunction "so." However, when the conjunction "so" is followed by a modal verb, a personal pronoun, and a verb, a comma is not necessary.

Here's another example:

• Incorrect: She studied hard, but she couldn't pass the exam.
• Correct: She studied hard but couldn't pass the exam.

In this case, the comma before the conjunction "but" is not needed because it is followed by the modal verb "couldn't," a personal pronoun "she," and a verb "pass."

When to use a comma:

Commas are used before these conjunctions when they connect two independent clauses, unless the clauses are closely connected and short.

Here's an example:

• Incorrect: I woke up late and I missed the bus.
• Correct: I woke up late, and I missed the bus.

In this case, a comma is necessary before the conjunction "and" because it connects two independent clauses - "I woke up late" and "I missed the bus."

Please note: To ensure your writing is mistake-free and grammatically correct, you can use the Linguix grammar checker, which automatically detects and corrects common grammar mistakes.