1. A complimentary remark is nice,
but a complementary remark is more useful
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2. A complimentary remark is nice, but a complementary remark is
more useful
Among pairs of words that are often confused is the
pair complimentary/complementary. Complementary is
not only far more common in scientific writing but also
has several specific meanings: a complementary
sequence of a piece of DNA, for example, or a
complementary angle (which, together with its partner,
adds up to 90 degrees). Then there is complementary
medicine, also known as alternative medicine, which
refers to treatments other than those followed in or
recommended by the traditional Western medicine.

3. A complimentary remark is nice, but a complementary remark is
more useful
Complimentary, on the other hand, either refers to
praise (as in "The reviewers complimented the
researchers on the originality of their approach" or
"The poster won many compliments for its attractive
design and clear presentation of information") or to
something given away free of charge (as in
"Complimentary copies of the special issue of the
journal were distributed at the conference" or
"Complimentary passes for the exhibition are available
for the participants").

4. A complimentary remark is nice, but a complementary remark is
more useful
Thus, while it is nice to be complimented, a
complementary remark - one that reinforces
what is said or presented - is even more
welcome.

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