Yes, you are correct. The correct phrase is "number of," not "number or." This is a common mistake that many people make while writing or speaking.

Common Mistakes in English Grammar

Mistake 1: Confusing "Number or" with "Number of"

One of the most common mistakes in English grammar is incorrectly using the phrase "number or" instead of "number of."

For example:

• Incorrect: We have a large number or visitors at the museum.
• Correct: We have a large number of visitors at the museum.

In the incorrect sentence, "or" is used instead of "of." This mistake can lead to confusion and affect the clarity of your writing or speaking.

Mistake 2: Using "they're," "their," and "there" interchangeably

Another common mistake is using these three homophones interchangeably, even though they have different meanings and uses.

For example:

• Incorrect: Their going to the party and they're bringing a gift too.
• Correct: They're going to the party and they're bringing a gift too.

In the incorrect sentence, "their" is used instead of "they're," which is the contraction of "they are." This error can lead to confusion and make your writing or speech less accurate.

Mistake 3: Misusing "its" and "it's"

Confusion between "its" and "it's" is a common mistake that can affect the overall clarity of your writing.

For example:

• Incorrect: The dog wagged it's tail in excitement.
• Correct: The dog wagged its tail in excitement.

In the incorrect sentence, "it's" is used instead of "its." "Its" is a possessive pronoun, while "it's" is a contraction of "it is." Such mistakes can undermine the credibility of your writing.

Linguix grammar checker is a helpful tool that can easily spot and correct these common mistakes for you.