Starting from the idea of difficulty the FSI estimate gave us, it will take you 2200 hours or 44 weeks to reach Japanese fluency if your native language is English. That's: 1 year if you spend 6 hours every day on your Japanese studies. 6 years if you study for 1 hour every day.
However, many experts believe it takes between 4 to 6 months of dedicated study to reach a beginner level. On the other hand, you can expect to spend at least 3 years studying to become fluent in Japanese with near-native level accuracy.
Even after obtaining an N1 certification, many learners continue to study more kanji and vocabulary to further improve their proficiency. You can achieve the same advanced level in 3-5 years of learning Japanese part-time.
Depending the length of your study time every day and how often you can practice alone, such as having speaking practice over Skype, listening to podcasts like JapanesePod101, reading and writing the writing systems, and actively trying to utilize kanji, you can learn intermediate level Japanese within 1-3 years.
To comfortably have a basic conversation in the language and recognize a few written words in a year, you will have to spend at least an hour every day studying the language. However, if your purpose is fluency, you may require another year or two to speak, read and write Japanese.
You may have heard recently that it's now impossible to study in Japan if you are over 30 years old. Luckily for those who fall in that category, this isn't actually true and it's actually never too late to chase your Japanese language dreams.
Learning Japanese isn't easy and it will take time. It's probably fair to say that you can expect a commitment of at least three years in order to achieve something resembling fluency. The average learner gets to the advanced level in three or four years.
Of course you can. Generally the study is forever, so you can start it anytime you want, and 40 is still so young. Of course you cannot tell how further you can go in your life, but don't worry. To learn a language is forever.
You Can Learn Japanese to a Good Level After Just a Few Months. Chris Broad (Abroad in Japan) shows that it's possible to survive in Japanese with as little as 6 months of studying. Fluent in 3 Months Challenge head coach Shannon Kennedy learned Japanese in 3 months to a conversational level (around A2-B1).
In short, Japanese is one of the more difficult languages for a native English speaker to learn. It takes much dedication and time. Learning the kana and how to pronounce the syllables is relatively easy, the grammar is about in the middle between easy and difficult, and the kanji is very hard.
Duolingo Is Great as a Supplement
It is great for learning vocabulary and seeing how words are used in context. However, it's generally not great for learning the “why”s or “how”s of language. This includes grammar and semantics–how words interact with each other to create different meanings.
Native English speakers, or those who do not have previous Kanji knowledge, need approximately 325-600 hours of studying for N5 and 575-1000 hours for N4 level. JLPT assesses mainly reading and listening skills, so you may need to put in some extra effort to write and speak at such levels.
There are more than 10,000 characters listed as kanji, which can be discouraging when thinking about learning Japanese. Yet in reality only around 2,000 kanji are used in everyday life.
I'd say a good and dedicated student is probably able to pass N2 in a year with enough elbow grease, and another year-ish for N1, but that's already quite a big pace. Your average learner will probably do N4~N3ish in a year, N2 in a couple of years, and N1 in 3-4 years.
It's a gateway language
Learning Japanese provides a 'gateway' to other languages with a similarly-high level of difference from English. Chinese, Korean and Arabic, for example, would all become easier to learn if you have an understanding of Japanese.
Never Too Old To Learn
In my online courses, I have many students who are in their 40's, 50's, 60's and 70's. The older student I currently have is 85 years old.
While a younger brain is more malleable and plastic, humans are still capable of learning when they're past that age. The brain can still form new neural connections! So don't fear if you are over 18 or 25 (oh, the memories!).
Greek is spoken today by at least 13 million people, principally in Greece and Cyprus along with a sizable Greek-speaking minority in Albania near the Greek-Albanian border.
Greek is a relatively difficult language to master, even more so for English speakers. But it's still easier to learn than Russian or Arabic. The reason many English speakers find Greek to be so difficult is that it's not closely related to the English language.
For the past 5 years of studying Japanese, I can say that 2 hours a day is more than enough to get you where you want. To give you a perspective on the matter, I would only study around one hour a day—every other day. If by 'fluent' you mean to hold a conversation, then around a couple of years.
Which means, it's one of the hardest languages to master. They estimate 2200 hours of study before you can reach fluency in Korean. Or 88 weeks of extremely intense study. But if you want a more accurate estimate of how long it will take you to learn Korean, you need to go deeper than the FSI estimate.
For starters, Japanese has three writing systems: hiragana, katakana, and kanji. Kanji includes over 50,000 different characters, however, you only need to know about 2,000 of them to be considered fluent. You also only need to know about 5,000 Japanese vocabulary words to be considered fluent as well.