Multiple Languages at a time.
Is it better to learn one language at a time? Or multiple? I see a lot of people here with at least 10 languages they are learning at once and often level 20 or above. So I'm wondering is it better to learn one or multiple?
It's mainly a matter of what amount of time you have available for learning.
Your brain will be able to assimilate whatever you have time to study in a day, provided that you have good sleeping hygiene and are sufficiently focused on what you do (which is also a matter of having good work habits).
However, obviously, the more you focus on one specific language, the faster your progress will be in this language, so it's up to you to decide if you have some time constraints into learning any particular language, if that's the case you should focus on this one.
The more you split your learning, the less progress you'll have each day on each unit, but that doesn't mean that over-all your progress will be diminished (it will be less noticeable though, which can lead to a lack of motivation). I wouldn't advise going beyond 3 languages at a time if you want to be able to see some significant progress in all of them, and I would advise having a main language no matter what, a language that you focus more efforts on.
Don't forget that levels displayed on people's profile can only increase, not decrease, which means that a person may already have sufficient knowledge in a language without studying it anymore. So a person with languages at level 20+ is not necessarily a person who is still daily practicing that language, maybe this person is simply doing some refreshing once a week/month or even not at all.
Short answer : only one or two new languages at a time, plus one or two you already master and want to maintain.
Long answer : I learn four languages :
Hungarian is entirely new to me, so I study it on workdays, 1/2 hour in the morning and another hour in the evening (at least 50 XP per day)
I studied Esperanto a very long time ago, it is not entirely new to me. So, I train one or twice a week, on wednesdays and weekends.
I already read and speak spanish although not very well. So, I keep it for the weekends in one long session of 100-200 XP
English is my work language, I just refresh it from time to time to keep my tree golden
I would like to add German and Russian but I know this would be too much : I could not give them as much time as I would like to progress, like one hour ervery day for each. So they will wait till my spanish and esperanto trees are over.
What I try to do is pushing every language forward in parallel. If I gain one level in one language, I work on the other ones so they gain one level too (At the moment, my Esperanto is lagging behind, it shouldn't)
Okay. So I am really only studying Mandarin and Japanese regularly now. Before they were out I was just jumping language to language to see what they are like. I Studied Esperanto and French together no problem before and ZH/JP together is going good.
If you are just messing around with languages for fun then choose however many you want. If you really want to be bilingual, trilingual, whatever... then focus on a max of two languages at a time; one language at a time if you want real results faster.
I've been learning four languages at once for awhile now. Progress on every language is slower but I'm still seeing it with each language. More languages inevitably means less focused, so it really comes down to whether or not that would demotivate you. A lot of people would probably be better off learning one language at a time.
People can practice a lot of languages on Duolingo,its not that difficult, but most of them dont even realise how difficult it will be to manage so many languages after Duolingo. Learning a language requires a lot of time for listening, reading, and speaking, so if those people tried to learn those 10 languages it would be impossible. Anyway you can also find people who are happy by just getting some basics of a few languages and then getting fluency in other languages.
What also matters, in my opinion, is how related the languages you learn are. I have quit the English-to-Italian tree and moved on to Italian-to-French. That means that at the moment, I'm learning two languages, but they are, of course, very similar in vocabulary and grammar, so I believe that everything I learn in French actually strengthens my understanding of Italian. The flipside is that you inevitably confuse the languages at times, but I think that in the long run, it can be quite beneficial to learn multiple, related languages at once.
Even though it's possible to learn multiple languages, it's really best to do one at a time. You'll have more time to study and practice all of the areas of one language and build it up. If you do one language, you'll likely get to advanced level in the same time you would be intermediate in two languages, and even lower with even more languages. Especially because you're learning Japanese, it'll take even more time because of the writing system than if you were learning a language with a simple writing system.
I have been learning Dutch and German at the same time for quite a while. Sometimes, it is helpful as your knowledge in another language may be similar to that of the language you are learning. However, I find it can be difficult when they are very similar as I can get words confused.