Can i understand when to use ie or ei? Crossword

An area of grass used to grow crops or keep animals
A person you know well and like a lot but isn't necessarily family
A hand-held piece of armour used to protect against arrows
The paper to prove you have bought something
When you trick or mislead someone
The toy used for riding down hills in the snow
Half of sixteen
The person a doctor looks after
A summary and rating of a book or a film
How tall somebody or something is