There are different ways to translate wpForo and separate wpForo components.
Please you these methods to translate wpForo plugin:
In Dashboard > Appearance > Menu admin page wpForo creates new navigation menu called “wpForo Navigation (wpForo Menu)” and attaches this menu to wpForo Menu location. This is the main, top forum menu. Here you can customize and translate all menus.
Reputation Title Translation
Navigate to Forums > Settings > Members admin page. Here you can see the list of reputation titles.
Missing phrases (If those are not inserted in POT file)
You can translate any phrase using Forums > Phrases admin page. Search for certain phrase, edit and put the translated value. If you didn’t find some phrase you can add it as well. just use the [Add New] button. Please note, the key of the new phrase must be the English version, the value can be the translated version.