is this sentence gram. correct?

For example, the genocide in Darfur shows not only history repeats itself when unacknowledged, but also progress is at a standstill if we refuse to resolve our conflicts.

should i have a THAT before the not only and after the shows?

Yes. The sentence would be smoother with THAT.

Yes.

For example, the genocide in Darfur shows not only that history repeats itself when unacknowledged, but also that progress is at a standstill if we refuse to resolve our conflicts.

If you wished to you could say:

1) the genocide in Darfur shows that not only

or

2) the genocide in Darfur shows not only that h istory...

Sra

writeacher do i have to write two that can i just write one before the not only?

It's better with BOTH that Writeacher wrote.

Sra

Yes, for parallel construction purposes.

http://grammar.ccc.commnet.edu/grammar/parallelism.htm

To determine if the sentence is grammatically correct and whether you should include the word "that" in specific places, let's break it down:

"For example, the genocide in Darfur shows not only history repeats itself when unacknowledged, but also progress is at a standstill if we refuse to resolve our conflicts."

The sentence appears to be grammatically correct as it stands. However, whether to include the word "that" before "not only" and after "shows" is a matter of style and personal preference. Both options can convey the intended meaning, but they slightly alter the structure of the sentence.

Option 1: With "that"
"For example, the genocide in Darfur shows that not only does history repeat itself when unacknowledged, but also progress is at a standstill if we refuse to resolve our conflicts."

Option 2: Without "that" (as per the original sentence)
"For example, the genocide in Darfur shows not only history repeats itself when unacknowledged, but also progress is at a standstill if we refuse to resolve our conflicts."

In this case, the word "that" can be optional, depending on your preferred style. Including "that" may make the sentence slightly more structured and formal, but omitting it still conveys the intended meaning clearly.