點解有D字串串下會有個咁既符號 ' ?

其實有好多reason

有D係因為簡寫, for example: coz', couldn't
另外係因為係口語
仲有一個係因為口音唔同既人講英文, for example, Indian speaks English
" i meet them yesterday"
-----> " i meet 'em yesterday"
it usually appears in the conversations

有些是簡寫．．ｅｇ．Coz' ＝because 　
有些是讀長音ｅｇ．Hallowe'en
有些是口語讀音ｅｇ．'tis