Difference between seen and saw

Another common error I see English speakers sometimes make is misusing seen and saw. Here’s the difference:

“Saw” is the simple past tense form of “to see.” “Seen” is also a past tense form of “to see,” but it the past participle. You can’t use past participles on their own in a sentence like you can with the simple past tense; they must accompany auxiliary (helper) verbs.

Compare these two examples:

• I saw the hot pepper.
• I had seen the hot pepper.

Memory tip: seen must have a helper verb!