How Long to Learn a Language According to the FSI
The FSI, US Foreign Service Institute, divides languages into groups of difficulty for speakers of English:
French, German, Indonesian, Italian, Portuguese, Romanian, Spanish, Swahili
Bulgarian, Burmese, Greek, Hindi, Persian, Urdu
Amharic, Cambodian, Czech, Finnish, Hebrew, Hungarian, Lao, Polish, Russian, Serbo-Croatian, Thai, Turkish, Vietnamese
Arabic, Chinese, Japanese, Korean
The FSI 5 levels of proficiency
The person is able to satisfy routine travel needs and minimum courtesy requirements. I have to admit that I have never found this minimum level really works that well beyond saying hello and asking for the bathroom.
Limited working proficiency
The person is able to satisfy routine social demands and limited work requirements. This is a limited ability to converse and really only a step towards real fluency.
Minimum professional proficiency
The person can speak the language with sufficient structural accuracy and vocabulary to participate effectively in most formal and informal conversations on practical, social, and professional topics. This is the first level that is useful in real situations. This probably corresponds to B2 on the European Framework of Reference. This is what I always aim for.
Full professional proficiency
The person uses the language fluently and accurately on all levels normally pertinent to professional needs. This is nice if you can achieve it but takes a long time.
Native or bilingual proficiency
The person has speaking proficiency equivalent to that of an educated native speaker. This is rare.
On this scale, I would call limited working proficiency above basic conversational fluency
FSI research indicates that it takes 480 hours to reach basic fluency in group 1 languages, and 720 hours for group 2-4 languages.
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