Translations not working - troubleshooting

Do you get an error message when translations do not appear to be working?

If yes, check the following:

1. The form field where language is chosen may be missing the data source selection ID: "DocumentLanguage" (this is case sensitive).
2. The term column in the translations data source may contain illegal characters.
3. The term column may have duplicate terms, which are not allowed. 
4. Reference to translations data source in plugin configuration may be incorrect. It must be the exact name of the data source - this means it must be case sensitive, and not including any blank spaces, which also count characters).
5. In the DocumentLanguage datasource, it is important that IANA is written in capital letters, not as iana. 

If no, check the following:

1. Is the translations plugin assigned to the template? (This is accessed under the templates section of the file editor).
2. Is the correct language chosen in the user profile?