One letter makes all the difference

Complimentary

This has two distinct meanings:

• expressing a pleasant  or congratulatory thought, saying that something about another person  is attractive, admirable or praiseworthy:

She spoke to him in a very complimentary way telling him he had worn well over the years.

The newspapers were complimentary about the team’s performance after their victory.

• Indicating that something is free of charge or done as an act of courtesy.

They found a complimentary bottle of champagne in their honeymoon suite.

The restaurant offers valet parking as a complimentary service.

The complimentary close used on letters is fast disappearing as email becomes prevalent.

Complementary

This also has two similar but separate meanings:

• completing a set or making up a whole or forming a complement (as in a ship’s complement)

In a right angled triangle the two smaller angles are said to be complementary, because together they always add up to 90 degrees.

The two complementary articles dealt with different aspects of the same topic.

• combining in such a way as to enhance or emphasise the others’ qualities

In a good team, each member contributes complementary strengths and skills to achieve success.

The different blue colours in his tie complemented the paler blue of his shirt perfectly.

You should try to choose a wine which complements your food.

He was a great believer in complementary medicine such as acupuncture, which he advocated should be used in conjunction with conventional medicine.