Two words if you want to say something is in progress.
Shortened to v for sports matches.
Means by way of, so you can say he travelled via Dover but not that she travelled via train.
Use First World War and Second World War, not World War One and World War Two or WWI and WWII.
Whose is possessive. “The man whose car was stolen.”
Who’s means who is or who has. “The man, who’s a police officer, had his car stolen.” Contractions are never used outside of direct quotes, however.
Young people of both sexes aged from early teens to early 20s. See Age.