I don't have..与I haven't ..的区别例如：I don't have time to go.I haven't time to go.1.请问这两句有语法错误吗?有什么区别?2.另外请问"eg."是什么的缩写,如下文中的eg.应该是举个例子吧:.正文.eg.i ain't got nothing3.请问为什么I am not 要写成"I ain't"而不是"I amn't"是不是跟读音有关?

同意：抓狗去喽和yfymargarate的观点，
类似于某些情况下的have got 和have的关系。
have这个词美式和英式用法习惯不同

我来回答：
1.don't have, doesn't have, didn't have 是美式英语
haven't, hasn't , hadn't是英式英语
2.抓狗去喽说的是一方面的道理；第二点是ain't 可以用于书面语，表示：1）古英语 2）文化低的人的用语，比如，马克吐温的作品经常描写那些下层人，所以经常使用这类用法

一个语法无误
一个语法错误
exempli gratia
ain't
1. Contraction of am not.
2. Used also as a contraction for are not, is not, has not, and have not.
Usage Note: Ain't has a long history of controversy. It first appeared in 1778, evolving from an earlier an't, which arose almost a century earlier as a contraction of are not and am not. In fact, ain't arose at the tail end of an era that saw the introduction of a number of our most common contractions, including don't and won't. But while don't and won't eventually became accepted at all levels of speech and writing, ain't was to receive a barrage of criticism in the 19th century for having no set sequence of words from which it can be contracted and for being a "vulgarism," that is, a term used by the lower classes, although an't at least had been originally used by the upper classes as well. At the same time ain't's uses were multiplying to include has not, have not, and is not, by influence of forms like ha'n't and i'n't. It may be that these extended uses helped fuel the negative reaction. Whatever the case, criticism of ain't by usage commentators and teachers has not subsided, and the use of ain't is often regarded as a sign of ignorance.·But despite all the attempts to ban it, ain't continues to enjoy extensive use in speech. Even educated and upper-class speakers see no substitute in folksy expressions such as Say it ain't so and You ain't seen nothin' yet.·The stigmatization of ain't leaves us with no happy alternative for use in first-person questions. The widely used aren't I? though illogical, was found acceptable for use in speech by a majority of the Usage Panel in an earlier survey, but in writing there is no acceptable substitute for the stilted am I not?

前者后接名词后者加动词过去分词

让我来完整的回答你的问题：
1 两句都对 当have表示“拥有”的意思时 两种说法都可以 你的意思是没有时间 have在这里表示“有”,所以两句话都对 但如“I don't have lunch” 则不能说成“I haven't lunch” 因为这里的have是表示“用餐”的意思 但第一种说法（don't have）是美式英语用法 更流行 更普遍
2 eg.是exempli gratia的缩写 是例如的意思
3 ain't是一个非常口语化缩写用法 可以代表am not,are not,is not,have not,has not（外国人为了口语表达的简洁 经常用ain't代替 而不再考虑到底该用am not,are not,is not,have not,has not中的哪个） 但要注意：这种说法仅限口语 书面中不会出现 也不要在书面考试中这么用哦
全是我自己打的 不选我就太伤心了啊 hehe

1.第一个句子对，第二个错
2.是exempli gratia 例如的缩写
3.=am not 也可用作are not，is not，has not 和 have not 的缩略语
ain't 作为 am not，are not，is not，has not 和 have not 的缩略语的用法已有很长的历史， 但是使用ain't 逐渐被认为是文盲的标志，这一坏名声目前为止还没有可能除掉。

1.一般have的否定在是在前面+don't/doesn't/didn't
可是当have作为"拥有"的意思或做完成时态的助动词时可以用haven't/hasn't/hadn't
2.exempli gratia 例如
3.其实ain't是口语中用的,不仅可以表示am not还可以表示isn't/aren't/haven't/hasn't
英语中没有amn't的缩写要么直接用am not要么用ain't
但在am的反意疑问句中用aren't i
ain't其实就有点像我们中文的文言文是以前的用法
就像以前用thou art表示you are等等