I don't teach spelling mistakes per se, but I definitely provide strategies for bolstering your vocab and contextual understanding of words.

Either way, I'm always happy to direct others to the proper sources whenever possible and the first one is on the house:

(From Chambers, 12th edition):

complementˈary adjective

Completing Together making up a whole, right angle, ten, an octave or white

If more is needed:

complement /komˈpli-mənt/ noun That which completes or fills up A number or quantity required to make something complete That amount by which an angle or arc falls short of a right angle or quadrant One of the parallelograms not intersected by the diagonal of a given parallelogram when it is divided into four parallelograms by straight lines through a point in the diagonal That by which a logarithm falls short of 10 All members of a set not included in a given subset (mathematics) That which is added to certain verbs to make a complete predicate That by which an interval falls short of an octave (music) Either of a pair of colours which together give white A group of proteins in blood plasma that combine with antibodies to destroy antigens (formerly called alexin; immunology) Fullness (of the moon) (heraldry) transitive verb /-mentˈ or komˈpli-mənt/ To be the complement of

ORIGIN: L complēmentum, from com-, intens, and plēre to fill complementˈal adjective

Completing

complementˈarily adverb

complementˈariness noun

complementarˈity noun

A concept, first adopted in microphysics, which accepts the existence of superficially inconsistent views of an object or phenomenon, eg which accepts a dual aspect of light (consisting of particles, as shown by certain experiments, and of waves, as shown by others)