Il ya a, c'est and ce sont

Ok, let's take "il y a" first. It means simply "there is/are" in the sense of that it exists or is present. For example: "Il y a de grandes montagnes en Autriche" -- "There are big mountains in Austria."

"C'est/ce sont" means "it is/they are". In this context "ce" is immutable and will never be "ces". "Ces" is a demonstrative pronoun and belongs to the family "ces, celles, ceux". It always needs a noun and is matched in number and gender to it.

Ce ne sont que des enfants -- They are only children.
Ces enfants se comportent bien. -- These children behave well.

Il y a des pommes fraîches? -- Are there fresh apples?
Ce sont des pommes fraîches. -- These are fresh apples.
Ces pommes sont fraîches. -- These apples are fresh.

Does this make it any clearer?

-- Chris (not a native speaker).

Thanks for your help Chris. Rewriting your answer without the discussion of "ces" I get: "il y a" ... means simply "there is/are" in the sense of that it exists or is present. For example: "Il y a de grandes montagnes en Autriche" -- "There are big mountains in Austria." "C'est/ce sont" means "it is/they are"...(and these are).... Ce ne sont que des enfants -- They are only children. Il y a des pommes fraîches? -- Are there fresh apples? Ce sont des pommes fraîches. -- These are fresh apples. So, if I understand correctly: Ce sont des enfants - These/They are children Il y a des enfants - There are children.

Yes, correct. Only "They are children" woukd be "Ils sont des enfants." Otherwise you surmise correctly. -- Chris.

Thank you Cécile and Chris.