單看yahoo的解釋,卻未必清楚
若你查看Cambridge Dictionarie Online,我們可以看到
skies Show phonetics
plural noun
the sky in a particular state or place:
For weeks we had cloudless blue skies.
We're off to the sunny skies of Spain.
所以,當我們形容某地區的天氣、氣候,而用天晴、天雨時,那時就要用skies這複數形,如:
a day of rain and cloudy skies.
the sunny skies of Italy.
還有本來sky是不可數名詞,但若受形容詞修飾時,我們則會說a sky或skies,如:
a patch of blue sky.
a starry sky/ (the) starry skies.等
希望幫到你!