sky前面用不定冠词还是用定冠词

问题描述

We can never expect ______ bluer sky unless we create a less polluted word.

It was a cold winter night and the moon was shining brightly across ______ night sky.

第一空a，第二空the。都是名词SKY为什么冠词不一样呢?

老师答疑

沅老师：

▲sky属于自然界独一无于的事物（类似的有sun, moon, earth等），其前通常连用定冠词。如：

Lightning lit up the night sky. 闪电照亮了夜空。

The sun was low in the sky now. 太阳此刻低挂在天空。

Swallows darted about in the sky overhead. 燕子在头顶上飞来飞去。

A helicopter appeared in the sky above them. 一架直升机出现在他们上空。

The constellations in the night sky cannot be directly equated with the heroes of Greek mythology. 夜空中的星座不能直接与希腊神话中的英雄相等同。

▲但是，当它们受到描绘性形容词的修饰时，如果不是特指，则其前要用不定冠词，此时的a含有 a kind of 的意思。如：

A cloudy sky is not always a sign of rain. 阴天不一定是下雨的预兆。

All I recollect is a grey sky. 我所记得的只是灰色的天空。

The sun beat down all afternoon from a clear sky.  整个下午晴空当头, 骄阳似火。

The weather broke and thunder rumbled through a leaden sky. 天气骤变，雷声隆隆响彻乌云密布的天空。

The hues of the leaves in autumn are beautiful against a blue sky. 秋天，色彩丰富的树叶在蓝天的映照下非常美丽。

In sharp contrast to her mood, the clouds were breaking up to reveal a blue sky. 乌云渐渐散开，露出了蓝天，这和她的情绪形成了鲜明的对照。

陈老师：

We can never expect ______ bluer sky unless we create a less polluted word.

It was a cold winter night and the moon was shining brightly across ______ night sky.

第一空a，第二空the。都是名词SKY为什么冠词不一样呢?

回答如下：

（1）抽象名词，独立无二的名词，如果前面有描述性修饰词或者限定词修饰限定时，可以加不定冠词，如果没有就加定冠词，或者不加冠词

例如：

(1) on a rainy morning 

(2)in the morning 

(1) I usually have breakfast at 8:00 every day.

(2) I had a wonderful breakfast yesterday

(1) a blue sky

(2)in the sky