是不是所有的形容词都可以+ly变为副词啊?

当然不是的
friend是名字 加ly却是形容词了
你说的只是大部分的情况
一、在形容词词尾直接加-ly.如:real-really; helpful-helpfully; careful-carefully; hopeful-hopefully; slow-slowly; quick-quickly; quiet-quietly
二、以辅音字母加y结尾的形容词要变y为i,然后再加-ly.如:busy-busily; angry-angrily; easy-easily
三、某些以辅音字母加不发音的字母e结尾和以-ue结尾的形容词要先去掉e,然后再加-y或-ly.如:terrible-terribly; true-truly; gentle-gently
另外,副词还可以由形容词加前缀a-得来,如:loud (adj.)-aloud (adv.)
此外,部分名词加后缀也可变成副词,如:part-partly.
例句:It is partly her fault.有部分是她的错.
需注意:friendly; motherly; lovely等词是形容词而非副词.
再看转化副词.在英语中,有些词既可以作形容词,又可以作副词,如early,much,fast,little,wide,loud等.由于这类词词性虽不同,但词形却一样,这就需要大家学会在特定语境中判断它们各自的词性.例句:Thank you very much.(adv.) 多谢.There is much water in the river.(adj.) 河里有很多水.The music is too loud.Please turn it down.(adj.) 音乐声太大,请调低点.He speaks loud enough.So everyone in the room can hear what he said.(adv.) 他说话的声音很大,所以房间里每个人都能听到他的话.
另外,还有一类副词和形容词词义相同,但拼写却不同,如well和good.例句He speaks good English.他讲一口流利的英语.He speaks English well.他英语讲得不错.
多音节y结尾的词 将y改为i后加ly easy-easily
happy-happily
heavy-heavily
单音节y结尾的词 直接加ly gay-gayly (gaily)
sly-slyly (slily)
以ve结尾的词 去e加ly true-truly
以le结尾的词 去e加y gentle-gently
possible-possibly
其他以e结尾的词 一律加ly nice-nicely
wise-wisely
polite-politely
以ll结尾的词 只加y full-fully
以ic结尾的词 加ally automatic-automatically
energetic-energetically
其他形容词 均加ly careful-carefully
glad-gladly