Here is a list of idiomatic expressions using the word well.

As well

As well means in addition to something or someone else. This expression mainly goes at the end of sentences.

• She not only sings; she plays the violin as well.

As well as

As well as connects two clauses.

• They need computers as well as books. (= They need both books and computers.)
• He went to Germany as well as France.

Be doing well

To be doing well is to be getting better after an illness.

• She seems to be doing well after beating cancer.

Be doing well for yourself

When you are doing well for yourself, you are successful in life.

• She has four children and all four of them are doing well for themselves.

Do well by someone

To do well by someone is to treat them in a fair or generous way.

• The religious leader urged his followers to do well by their fellow human beings.

Know full well / know perfectly well

To know something full well is to know it while pretending not to.

• You know full well what I am talking about.

May as well do something / Might as well do something

This expression is used to suggest that it may be a good idea to do something.

• We may as well ask his help.
• We may as well consult a specialist.

Well done

This expression is used to congratulate someone when they do something well.

• Well done, Mark!