The trick is one-syllable words to represent each letter in the alphabet, but they have high phoneme diversity (sub-syllable unique sounds) and care was taken to ensure they can be differentiated even when saying them “too fast” in a stream without gaps, and I tested them extensively to make sure I picked words that didn’t clog up your mouth too much. The result is I can type 58wpm for short bursts using the alphabet alone, which is enough to play ztype, write entire words that would be hard to dictate, and control vim directly without an additional command set.
The base alphabet is:
air bat cap drum each fine gust harp sit jury crunch look made near odd pit quench red sun trap urge vest whale plex yank zip
Go ahead, see how fast you can read the alphabet in order. Then try reading it even faster, blurring the word boundaries together a bit. You can still tell the words apart!
Some people change a couple of words if they don’t work well in their accent, but the base idea holds strong.