I started in mainframe languages, and have moved across to modern languages. I have a set of things that I perform in any language to gain familiarity: loops, nested loops, lists, arrays, dictionaries and other data structures, control structures, etc. All of the basic things that you know you will need. Then I usually set about how to setup testing - at least unit tests. I use TDD, so this is vital.
It only takes a few hours to go through these basics and get a tour of the language. I try to sit next to someone who is using the language if possible - they often have tips and tricks that they have found through trial and error, and can cut time off your learning.
I can generally become productive in a few hours. That affords me time to learn the deeper structures of the framework as I go along. Having that initial core understanding really reduces issues down the road.
It only takes a few hours to go through these basics and get a tour of the language. I try to sit next to someone who is using the language if possible - they often have tips and tricks that they have found through trial and error, and can cut time off your learning.
I can generally become productive in a few hours. That affords me time to learn the deeper structures of the framework as I go along. Having that initial core understanding really reduces issues down the road.