niieani
The other story is I got a girlfriend speaking the other foreign language (Slovak). We speak English and her language (foreign for me) interchangeably. We also lived in her country for some time. Time we spent speaking, listening and reading her language made me fluent. No special tricks, courses, apps...
Just practice, asking questions and learning. I got fluent in about a year, but bare in mind, Slovak and Polish (my native) share a common root, so it wouldn't have been as easy with something like Chinese or even French.
Unfortunately that's something TypeScript doesn't tackle, but you can use external libraries for floats, where you work on floats as... strings.
That alone makes TypeScript worth the trouble IMHO.
Obviously — you should always use common sense and choose the programming language to your needs.