Self-tutoring about pain relievers: the tutor shares some research. NSAID: non-steroidal anti-inflammatory drug; eg, aspirin, ibuprofen. Source: rxlist.com

Self-tutoring about English: the tutor brings up an issue he’s thought of for decades. Licence seems to be a noun, while license, a verb. Source: Gilmour, Lorna (editor). Collins Essential Canadian English Dictionary and Thesaurus. Glasgow: HarperCollins Publishers, 2006.