I was once told not to end "firstly [point 1], secondly [point2], thirdly [point 3]" in -ly and to leave them as first, second, third etc. Is this always true or only in certain situations? Is it ever ...
What to say if I want to tell approximate number of something. What should I say? E.g. I have (around/ about/ some) 5 books. Is there a rule for number approximation?