Rewrite the following sentence to make it more concise:
The referendum was held by the government in the month of August.
The Government held a referendum in the August.
Please check my work.
If you remove "the" before "August" and use a lower-case "g" on "government", it'll be fine!
The trials were held by the allied power to bring Nazi war criminals to justice.
how do I fix the were held part
Your work is almost correct. Here's a revised version:
The government held a referendum in August.
This version is more concise while still conveying the same information.