They both refer to wing movements here, but they don't have the same meaning. 'Flap' suggests a larger and possibly slower movement. 'Flutter' is a rapid succession of small light movements. 'Flutter' is what a butterfly does. The difference is clearer if you think about what a person might do. You can flap your arms, because arms are large and fairly heavy limbs. However, you might flutter your eyelashes - like a butterfly - because eyelashes can make a lot of very light movements in a short time. There are many verbs in English ending in '--tter' which suggest a light repeated movement : twitter, flitter, pitter-patter, glitter, mutter, spatter, splutter, jitter, skitter, titter, totter, scutter, for example.

Taeko, varieties of English don't vary nearly as much as foreign learners think that they do. The differences are nearly all in spoken and colloquial language. When it comes to standard vocabulary such as this, there is almost no difference at all. Written language actually varies very little. Apart from minor spelling conventions, written American and British English is virtually the same. Ignoring the spelling differences, it's possible to read an entire book and not know whether the writer is American or British.

Hi Poe, It's a fair question - sometimes authors want to add emphasis so they use two or three words which are almost synonyms. For British English; We use flutter for more gentle movements; such as a butterfly or a light curtain in the breeze. We use flap for a bird which flaps its wings or a person who is stressed and anxious! ;)

the best way is to search for google, and try to see the different. images definition which will be more practical for you see the differences ;) Remember, English and American English have got many different nuance so verify which language you are using :)