I haven't posted my introduction yet, but I plan on it. I've been playing after a 20+ year layoff, and tonguing turned out to be one of the harder things to recover (It's okay now). I can't say for certain, but it seems to me that having worked on it for a few days in a row I can maybe single tongue faster than back in my playing days. Of course then I went to work on double tonguing, and have that nearly ironed out. My question is: at what point do you decide to switch from single tonguing to double tonguing? Only when you can't single tongue the passage fast enough? What if you can comfortably play it either way? I had always assumed that you single tongue it if you can.