Answer:
The letter S is added to pluralise most words in the English language. eg. Letter to Letters Word to Words and Language to Languages. But I am a word that is pluralised with the addition of the letter C.
I carry you down a gentle stream.
Cloud is my mother, wind is my father. What am I?
What has four wheels and flies?
I can be simple or I can be complex. I can be found in this riddle or in everyday life. I can be shapes or even colors.
In your fire you hear me scream! Creaking and whining yet I am dead before you lay me in your hearth.