I'm sorry, but whoever taught you about grammar in that appalling manner not only showed stupendous moral deficiencies, but also had a very poor grasp on tenses.
Noun inflections notwithstanding, where -s is one of several plural markers, non-modal verbs require an -s or -es ending in the 3rd person singular present simple to denote the
realis or
indicative mode in the active voice. Leaving off the -s/-es changes the mode to the subjunctive.
"I want you to know that you matter. I want you to know that your lives matter, that your dreams matter." (Barack Obama, 03 June 2020)
