How would you punctuate this sentence He will never understand it in a thousand no make that million years?

Here are a couple of ways to punctuate the sentence, along with explanations:

Option 1: With an exclamation point

* He will never understand it in a thousand—no, make that a million—years!

This option emphasizes the speaker's strong feeling that the person will never understand. The dashes set off the parenthetical phrase "no, make that a million" and the exclamation point shows strong emotion.

Option 2: With a period and a comma

* He will never understand it in a thousand—no, make that a million—years.

This option is more matter-of-fact. The dashes again set off the parenthetical phrase, but the period at the end makes the sentence declarative rather than exclamatory.

Choice depends on context:

* Use the exclamation point if you want to convey frustration, disbelief, or humor.

* Use the period if you want to be more neutral in your tone.