Server Problem

Hello everyone, I have a problem with my server. Everytime I download a big plugin like skywars,factions,etc..(not the small ones like essentials,worldedit,etc..)it changes the text to a different language. For example when I put Factions into my plugins and went on my server, when I typed in /help and what it usually would do on the bottom is say "Type help 2 to go on the next page" or something like that. Instead what happened is it said it in a whole different language I didn't know. Also when I put skywars in my plugins and went on the server and typed /skywars help it gave me all the skywars commands in english, but the description of the command was in a different language. I don't know if this is common or if this is suppose to happen, but please reply back if you know about this problem. Also when I say command description mean like(this is only a example) /home Teleports you to your home. Please reply back ~Thanks

Where would the configuration be?