The Foreign Service Institute (FSI) has created a list to show the approximate time you need to learn a specific language as an English speaker. After this particular study time you will reach “Speaking 3: General Professional Proficiency in Speaking (S3)” and “Reading 3: General Professional Proficiency in Reading (R3)”
Please keep in mind that this ranking only shows the view of the Foreign Service Institute (FSI) and some language students or experts may disagree with the ranking.
If there is a language in this list you would like to learn and it is in a high difficult category, don’t let this stop you from learning it. Even if they are ranked as difficult, it does not mean that they are impossible to learn and maybe it is not hard for you at all.
Category I: 23-24 weeks (575-600 hours)
Languages closely related to English
Category II: 30 weeks (750 hours)
Languages similar to English
Category III: 36 weeks (900 hours)
Languages with linguistic and/or cultural differences from English
Category IV: 44 weeks (1100 hours)
Languages with significant linguistic and/or cultural differences from English
Persian (Dari, Farsi, Tajik)
Category V: 88 weeks (2200 hours)
Languages which are exceptionally difficult for native English speakers
Mandarin (Chinese) *Japanese
* Languages preceded by asterisks are usually more difficult for native English speakers to learn than other languages in the same category.