When to use each mode
Common words rehearse the 200 most frequent English words: good for rhythm once the alphabet is unlocked. Sentences add capitals and punctuation, which is where “I type fast except in real writing” usually lives. Paragraphs are for endurance: keeping form after the first minute. Weak keys is the one that actually moves a plateau. It reads miss counts stored in this browser and builds a drill from them, similar in spirit to keybr, sitting after the curriculum on purpose.
Practice vs a typing test
Practice trains. A timed test measures. If you still look at the keyboard, start with how to learn touch typing and lesson one, not with another round of common words. If you already type and want a higher WPM, the how to type faster guide is the method; weak keys is the drill. Programmers: brackets, operators and indentation get their own mode in code typing practice.