Speaking is a skill, like playing guitar. It's made up of a bunch of smaller skills, including:
- Physical skills, like pronouncing a particular sound, or transitioning between two sounds; as well as
- Mental/memory skills, like remembering how to use a particular grammar pattern, or remembering what the word for rollercoaster is.
The more you practice these skills, the more quickly and accurately you can perform them. But speed doesn't come from practicing quickly; it comes from practicing slowly. That's because, when you slow down, you can make sure you're making the physical motions correctly. You can make sure you're putting your words together the way you want to. And most importantly, you can pay attention and avoid making the same mistakes over and over.
Why is that important? If you keep repeating the same mistakes, you'll practice those mistakes. That means it'll get easier and easier for you to make the same mistakes every time you speak! The only way to avoid that is to give yourself plenty of time for slow practice.
Of course, you have to make mistakes to learn. You can't be timid, and you can't be afraid to fail. But your goal should be to identify your mistakes, then fix them and practice the correct skill slowly. Making mistakes is good; repeating mistakes is bad.
Since the brain develops skills over time, the most effective form of slow practice is to keep practicing slowly every day. Ideally, when you're learning a new skill (such as saying the [θ] sound, or learning a new grammar pattern), you want to practice every day for at least five days before you even try speeding up.
If you find yourself making mistakes with skills you learned a long time ago, do the same thing. Pretend you're a beginner and practice as slowly as you need to. Later on, when you use the skill again, you'll find it's easier and easier to do it properly!
We often feel like we're under pressure when we're speaking a foreign language. We feel like we should be talking faster, or we feel like we're expected to perform at the same level and speed as a native speaker, even though we're still learning. But if you relax and take it at whatever pace you think is best, you'll actually end up communicating better. Imagine talking to someone learning your native language:
- Would you rather hear them speak slowly but clearly?
- Or would you rather hear them speak as fast as a native speaker but with mistakes that make them hard to understand?
I think the choice is clear.