The other day I got tagged on a Twitter thread started by Wicked Witch of the Test about people with a background in linguistics who’ve ended up in testing. That prompted me to think about the language concepts I've found valuable in my day job, then I started listing them, and then realised how many of them I've mentioned here over the years . This post is one of an occasional series collecting some of those thoughts. --00-- If you're not familiar with the term syntax, you've probably heard of it by another name, grammar . It's the set of rules that defines the acceptable combinations of words in a language. Most native speakers have an instinctive grasp of it in their language, even if they were never taught it explicitly. Knowledge of English syntax is what can tell you that the first two of these are legitimate structures (even if the second makes no sense) and the third is not: As a customer I want to log in using two-factor authentication to protect...