To supplement, or complement?

[Mehrgan]

Hi there,

Could anyone please tell me the difference?


Thanks...

[Barb_D]

When you supplement something, you add something extra. You may supplement your regular income by doing freelance work.

When you complement something (and it's so often mis-spelled as compliment that I sometimes wonder if most people realize they are different words), you have things that work well together. A dress may complement my eyes. You choose furnishings so they complement each other.

[Mehrgan]

Many thanks to you dear Barb_D...

[Abstract Idea]

----- I am not an ESL teacher -----

Although Barb_D gave a nice explanation on the difference of these words I think there are many situations in which these words are used as synonymies. That is why I prefer math to language.

In math, complement, supplement and (replement?) are the values which should be added to an angle in order to make it 90°, 180° and 360° respectively.

I am not sure of the word "replement", in Portuguese we say:
"complemento", "suplemento" and "replemento". But I couldn't find an English word for "replemento", which word would one use for it?

[tedtmc]

Two parts complement each other to make something complete or wholesome.
eg. the two partners of the company have different skills which complement each other.

In Maths, you also say that 30 degrees and 60 degrees are compementary.

To supplement is just to 'add on' eg. he works part-time in addition to his full-time job to supplement his income.

not a teacher

[Abstract Idea]

In Maths, you also say that 30 degrees and 60 degrees are complementary.

And you also say that 30 degrees and 150 degrees are supplementary.

See for instance these two wikipedia short articles (good to practice one's technical English):
Complementary angles - Wikipedia, the free encyclopedia
Supplementary angles - Wikipedia, the free encyclopedia