First of all, what they probably meant to say was to use more precise/active/engaging/powerful/and just better verbs than the ones you used. What they didn’t know is that a “strong verb” has nothing to do with any of that. Neither do weak verbs, for that matter. Strong verbs and weak verbs are determined by how their past tense is formed. Weird, I know, but it’s true.
In general, a verb is considered a weak verb (also called a regular verb) if the past tense is formed by adding -ed, -d, or -t to the base form of the verb, such as with kick/kicked and mark/marked.
In general, a verb is considered a strong verb (also known as an irregular verb) if the past tense is formed by altering the vowel of the present tense form, such as with sing/sang and give/gave.
The abuse is widespread. Just google “strong verbs” and you’ll find lists and lists of “strong verbs” that have nothing to do with actually being strong verbs. And some are from .edu sites where people should know better. Well, this is your chance to take a stand and sound rather astute.
The next time someone tells you to use strong verbs, just roll your eyes and quote Inigo Montoya. And the next time you want to help someone with their boring verb choices, tell them to use better verbs, or powerful verbs, or more active verbs. Just don’t tell them to use strong verbs, unless of course, you’re the type of troll who cares nothing for proper English grammar and usage and doesn’t mind warping the minds of innocent children preparing for standardized tests that determine their academic futures and in turn influence their legacies as English-speaking human beings.