Great question!
Because you asked it in a very specific way, the short, and definitive, answer is: Yes, I have. I am a native English speaker and Spanish is the first, and to date only, foreign language I learned.
The bad news is that I have no data points other than myself. Moreover, I have yet to see any YouTuber, linguist, webpage, or anyone else properly apply this metric, even when they think they are, and even if they are people I greatly respect and admire. Granted, I know I don’t get “out” much, even on the Internet. This is the only forum I participate in and that comes in spurts. I also don’t stay too current on developments in the field.
Nevertheless, over the years, my impatient self has many times asked the universe “How long does it take to learn a language?” In my opinion, the best answer ever given was Master Steve’s: “A long, long time.” Thanks to you, the World Wide Web will now have the second best answer here.
When people ask me, “How long have you been studying Spanish?” I could tell them 28 years. But that would make me what that hot Slovakian polyglot who liked to wear red (Lydia something?) calls a “timekeeper.” Instead, I perplex them by saying “15-1700 hours.” I’m estimate my middle and high school Spanish amounts to between 200-400 hours, but I’m not sure. On the other hand, I have invested 1,306 hours, 40 minutes of self-study and that I’m damn sure of, because I counted every one them for this very reason.
First things first. Each “week” of learning at the Defense Language Institute comprises 25 hours of “class hours,” five per day, five days per week. For the lower end languages of 24 weeks, like Spanish, that’s 600 class hours. For the slightly harder languages you spend 30 weeks doing, like German, that’s 750 hours. However, you must also include the three hours of homework per night they also do. Students at DLI make language learning their full time job, which is, not coincidentally, 8 hours per day or 40 hours per week. (Five in class, three of self study). So, one week equals 40 hours of learning time.
So for Category 1 Languages: 960-1200 hours to reach proficiency.
For Category 2: 1,440 hours.
Category 3: 1,760 hours.
Category 4: 3,520 hours.
If you’ve got nothing else to do and have 10 hours a day to focus on Mandarin like Steve in Hong Kong in 1968, yeah, you’ll do it 10 months like he did. If you put the time in Steve does now ( 1 to 1.5 hours a day/about 500 hours a year), it will take you:
Category 1 Languages: About 2 years to reach proficiency.
Category 2: About 3 years to reach proficiency.
Category 3: About 3.5 years to reach proficiency.
Category 4: About 7 years to reach proficiency.
If you’re like me, and slack off for months or years at a time, it’ll take you 20 years. Incidentally, I take the same approach to physical fitness. But either way, I got to a B2/Level 2/professional proficiency/fluency/whatever in 900-1,000 hours—the same about of time as working an FSI/DLI schedule of 40 hours for 24 weeks.
All this being said, we have a few caveats to remember:
-
This is for English speakers. (if you’re going from Spanish to Italian or Portuguese it’s going to be faster or at least easier).
-
Again, we have no other data points or anecdotes that I know of outside of me tracking the time this way outside of the classroom/fsi teaching model.
-
What t_harangi brings up. I don’t know specifically how “our” self study stacks up to the DLI experience. I have no doubt it is superior to “regular” classroom environments, but DLI has very small, very intensive, very personalized programs taught by experts who just do this and students that tend to be older, experienced language learners who are very motivated. I think to these probably balance each other out and thus make them comparable, but we don’t know for sure.