far做adv, 表示远的时候,可用在肯定句中吗?

Question

far做adv,表示远的时候,什么时候用在肯定句中?
在朗文词典中指出：far 作为adv，表示远的时候，主要用于疑问句和否定句
不说：The airport is quite far。 要说：The airport is quite a long way away机场很远
在牛津词典中，far 作为adv，表示远的时候说：far 主要用于疑问句和否定句，肯定句较常用 a long way ，并且指出正误句子：
误：We went far. 正We went a long way.
正：The restaurant is a long way from here.
但是，同时在这个牛津词典far的用法上，也有far表示远而用在肯定句的例子，
如牛津：Far away in the distance, a train whistled. 远处有一辆火车鸣笛。
另外在韦氏词典上也有有far表示远而用在肯定句的例子：
The dog wandered far from home.狗在离家很远的地方游荡。
She lives far out in the country.她住在乡下很远的地方。
请高手指教为什么会出现这种混杂情况，这不是前后矛盾吗？难道far作为adv，表示远的时候,是可以用在肯定句中吗?

Answer 1

首先，我不是英语专业的人，以下答案全凭个人猜测。感觉你这个问题有点钻牛角尖了。每个辞典对词的解释稍有出入也是正常的。然后针对你所说的几个病句，比如The airport is quite far里面，far本身也不是adv词性，这个句子应该是个主系表结构，如果改成The airport is far away会更好。
然后we went far，在语感上有问题，要硬说语法不对能我也挑不出毛病，可能就是用far来修饰go这个动词很别扭，就像不能随便给一个名词安上形容词一样。比如一个很中式英语的错误表达，the price is expensive，我们认为用expensive修饰price好像没有什么问题，语法上也说得通，但这句话就是不对，因为price只能说low或是high，而不是cheap或是expensive。同理用far修饰go就很别扭。如果改成we teaveled far就会好很多。
所以我认为的是far在adv词性意思为很远的时候，是可以用在肯定句里。大部分情况跟away或是from一起用。

Answer 2

English is a living language just like Chinese. It is dynamic and forever changing. It becomes difficult for English students to find a set rule to all adverbs.
Adverb - a word to modify a verb, an adjective, a clause, a preposition or even a sentence. It can be a single word or as multi-word as in adverbial phrase or clause. Adverb is used to answer these main questions in a sentence: on how, when, where, in what way and what extent. Many later linguists put words that does not belong to other 'parts of speech' into adverb.
I have digress. Sorry.
Coming back to your question, far is an adverb which can be used to express in distance, expanse in space and time, plus also quantity. People seldom use far only with a negative connotation anymore.
Far used to give feeling of distance: The airport is far away. The airport far in the distance.
Far used to give vastness: He had travelled far and wide to find this particular doll for his daughter. Motivation is the drive for me to come so far and done so well
Far as quantity: Your service is far from my expectation. I function far better if someone gives me encouragement.
These examples show you the use of the word far as adv only.