I frequently hear sentences constructed in this way.

Problem:
A verb’s past participle appears on its own where the verb’s past-tense form should be placed.

Explanation:
This problem is the complement to what I posted yesterday.

In other words, there seems to be a tendency among some American English speakers to mix the past participle with the past tense.

The past participle of the verb “see” is “seen”, and “seen” requires an auxiliary verb — in the present or past tense — to form a perfect tense.

Otherwise, the past tense should be used in place of “seen”.

This gives us three solutions, depending on the intent of the speaker.

Solutions:
“I saw him.”
OR
“I have seen him.”
OR
“I had seen him.”

I frequently hear sentences constructed in this way.

Problem:
A past-tense verb appears where the verb’s past participle is required.

Explanation:
The auxiliary verb “has” must be combined with a past participle to form a perfect tense.

Here are some examples:

• He has eaten the piece of pie.
• He has shaved five minutes off his marathon time.
• He has cut his finger.

The first example uses “eaten” — the past participle of “eat”.

The second example uses “shaved” — the past participle of “shave”.

The third example uses “cut” — the past participle of “cut”.

The past participle of “run” is “run”, not “ran”, which is the past tense of “run”.

For fun, I searched Google for each of the following combinations (with the quotation marks) and got about the indicated numbers of matches:

• “has run” — 6,780,000 matches
• “has ran” — 203,000 matches

This tells me that Web authors favor “has run” over “has ran” by a 33.4:1, which is good but not great.

Solution:
“He has run five miles.”