A lonely grandmother can't keep up with a young oneA lonely grandmother can't keep up with a young one
Other girls are more cheerful, but this one is also goodOther girls are more cheerful, but this one is also good
One of the fastest and most beautiful cars in the world. porscheOne of the fastest and most beautiful cars in the world. Porsche
Harry potter and the one whose name cannot be pronouncedHARRY POTTER AND THE ONE WHOSE NAME CANNOT BE PRONOUNCED
If this phone survives, then i want one for myselfIf this phone survives, then I want one for myself
Без других, в отдельности. Тот же самый, тожественный. Единый, целостный. Число, цифра и количество 1. Какой-то, некий. Только, исключительно. Какой-нибудь в ряду сходных.