Updated: Feb 15
To put it simply, just three things: motivation, patience, and time.
You probably already have motivation - otherwise, you wouldn't be searching the web for tips on how to learn a language... And this is a huge first step! This motivation is what will make you open that language app on your phone when you have 5 minutes free, look for a language exchange partner, and practice what you've learned with friends and strangers alike. Your interest in learning a language will keep you going and will make it exciting and fun. Remember your language lessons in high school? Many of you had to take Spanish or French because it was a requirement, rather than to genuinely learn how to speak another language... and how effective that learning was? You were probably lucky to learn how to introduce yourself, but I'm yet to meet someone who became fluent in language classes in school alone. Those who did learn a language managed to do so because they looked for other resources and opportunities, and studies a lot on their own. And that required some motivation!
You'll also need patience - and lots of it - because it will take time to build vocabulary, start speaking comfortably, understand the news on TV in your target language, and have a proper conversation with a native speaker. And it won't always be easy to make sense of all the foreign words, sounds, and rules. But the exciting news is that as you keep learning, it will get easier, and you really CAN have your first conversation in a language just a few weeks after starting learning it (and you'll suddenly start picking up on the chats other people have around you in a language you are learning). To make this happen, you'll need to set aside time for working on your target language every day, even if only for 30 minutes.
Now, about the time you'll need to learn a language (the third key ingredient to this challenge of becoming fluent in a language)... How long it takes to learn a language will depend on the language, your attitude, the time you spend with the language, and your attentiveness to the language. The US Foreign Service Institute estimates that for an English speaker, learning a Romance language (such as French, Spanish, Portuguese, or Italian) should take about 480 hours to reach fluency. That's about a year if you study 2 hours a day on average. Just think - only a year to be fluent in these languages (and much less to reach conversational fluency)! For languages that are very different from English (such as Chinese and Japanese), it may take twice that long, but that time will be reduced if you work on the language regularly and devote more daily time to learning and practicing.
Now, your daily time spent on learning a language doesn't mean you need to be in a classroom for two or more hours a day. In fact, I've found that as a beginner, a classroom setting is probably the worst use of your time and money to start learning. Today's technology and language-learning tools give you a great range of effective options that you can explore on the go (like podcasts that you can listen to on your daily commute), during your coffee break (like interactive and fun apps that help you learn vocabulary and grammar through games and quizzes), and even when you are exercising (like pre-recorded audio lessons available from several reputable resources). My daily language-learning routine includes listening to audio lessons from Pimsleur when I take my shower and brush my teeth in the morning, watching a YouTube lesson during breakfast, spending 20 minutes on an app like Drops or Memrise on my commute to work, spending a non-interrupted hour working on a Rocket Language class at lunch or in the evening, and then chilling a bit before going to bed by watching a film on Netflix in the language I'm learning).
What's really important for being able to progress quickly in a language (in addition to finding time to work on it every day) is engaging all your senses as early as possible in learning it. This means listening to the language as much as you can to get used to its melody and pronunciation, growing your vocabulary focusing on words you will likely to use in real life, reading simple phrases to see how the words look and fit together, and speaking very early on - even if it's just basic phrases - to get over the common fear of communicating in a foreign language that some learners never get over... And today there are dozens of affordable and effective resources that can help you achieve these goals.
I've been experimenting with such resources for the last twenty years - and I'm amazed by the incredibly fun and effective new tools that became available in just the last few years. Using the tricks and methods I've tested myself, I've now reached fluency in four languages in addition to my mother tongue, and I'm working on four more using the same methods and tools I share with you on Perfectly Fluent.
Let me know in the comments what your language routine looks like, and what tools and tricks you've found most effective to progress in the language you are learning!