The Oxford comma is the final comma in a list. Some guides require it, others do not, but clarity and consistency matter most.
schedule
Engineering Constraint Language Exercise
CEFR C2; focus on precise constraint language used in engineering specifications, standards, design reviews, and test protocols.
Attitude Vocabulary Exercise
B2 Upper-Intermediate ESL multiple-choice gap-fill exercise on attitude vocabulary.
Nauseous can mean nauseated
Many people use nauseous to mean feeling sick. That use is now widely accepted, even though some guides once preferred nauseated.
Who vs. whom: when the old object form still matters
Use who for subjects and whom for objects. Whom still appears after prepositions and in formal writing, even if speech often prefers who.