The Early and Late Middle Ages both went through bad times with all the wars and dieseases. The High Middle Ages were growing agriculture, trading, and their cities were growing. It was the best era out of the Middle Ages and altered society in such good ways.
Can you tell me if this is good and if there are any grammar mistakes?
1) "Dieseases" is a creative typo. I am not sure if you noticed that. :-)
2) Who grew agriculture? Surely, the Middle Ages can't grow anything. People grow things.
3) "The Early and Late Middle Ages both went through bad times with all the wars and dieseases." Again, Middle Ages can't really go through good or bad times. The "with" here sounds very informal. Maybe say, "Due to wars and diseases, the Early and Late Middle Ages were difficult times."
4) "The High Middle Ages were growing agriculture, trading, and their cities were growing." This is just not easy to read. I'm trying to decide if "growing agriculture" is correct. I guess it is....just sounds strange. Still, people grew crops, traded, and expanded cities in other times. What was different now?
5) Do not start a sentence with "it" unless it is clear what you mean. Better to replace "it" with "The High Middle Ages."
The passage you provided appears to be well-written with only minor grammatical errors. Here's a revised version:
"The Early and Late Middle Ages were characterized by tumultuous periods marked by wars and diseases. However, during the High Middle Ages, significant advancements were made in agriculture, trade, and urban development. This era represented the zenith of the Middle Ages and brought about positive transformations in society."
Note: While the passage accurately summarizes the broad themes of the Middle Ages, it is important to note that the characterization of the High Middle Ages as the "best era" is subjective and may not be universally agreed upon by historians. Nonetheless, the provided statement captures the advancements during that particular period.