accident(ally) actual(ly) address answer appear arrive believe bicycle breath breathe build busy/business calendar caught centre century certain circle complete consider continue decide describe different difficult disappear early earth eight/eighth enough exercise experience experiment extreme famous favourite February forward(s) fruit grammar group guard guide heard heart height history imagine increase important interest island knowledge learn length library material medicine mention minute natural naughty notice occasion(ally) often opposite ordinary particular peculiar perhaps popular position possess(ion) possible potatoes pressure probably promise purpose quarter question recent regular reign remember sentence separate special straight strange strength suppose surprise therefore though/although thought through various weight woman/women