There are four ways that I learned to express ‘and’ in Korean. One is through particles 과/와 (gwa/wa) which is used to connect nouns, 과 attached to noun ending in vowel while 와 for consonant. The two other particles are 하고 and (이)랑 or hago and (i)rang as Romanized. Although 하고 can also mean with it also means and. The last one is used to connect ideas, phrases or clauses by attaching -고 (-ko) to verb which I have more recent post about.
This time I am introduced to another two shape ending which function the same as above is -(으)며 or (eu) myeo. It can be compared to the one shape ending -고 (-go) however (으) 며 is more bookish, it is not used in spoken Korean. Also, this two shape ending is limited to mean and or sometimes while but never as the other functions -고.
Here is an example:
오늘은 비가 와며 내일도 비가 오고 추울 거에요. (Oneureun biga wamyeo naeildo biga ogo chuwoyo.) Today it’s raining, and tomorrow it will be raining and cold too.
When (으)며 is added to a verb that is considered as l-extending like the word 살 (sal), the l is retained. I have noticed this pattern to be true for all two shape particles; the l-extending verbs keep the ‘l’.
It Started with Hangul 
Please note that it should read “비가 오며” and not “비가 와며”.
“과 attached to noun ending in vowel while 와 for consonant”
isn’t it the other way around?
bydwei, i jus found your site. and i lav et!! ^_^ ill be reading your posts and will be waiting for future additions. thanks for sharing these ^_^
i am a bit confused here as well because the books says otherwise. I’ll confirm it with a Korean friend.