Many native English speakers would say that it is "women's clothes". However, when I asked non-native English speakers, they say that "women clothes" would be preferred by them.
In the UK many department stores advertise that they sell women's clothes, men's clothes and children's clothes. However, we need to decide if “women('s)” in “women('s) clothes” is a possessive noun or a nominal premodifier or attributive noun functioning as an adjective, “women”, whose head is “clothes”. A Wikipedia page states that fluent English speakers will regard the use of "women clothes" as solecistic (=grammatically incorrect) in this context.
It seems that, when asked, native English speakers will prefer reading “women's clothes” in a department store while non-native English speakers will prefer “women clothes”. Whilst native English speakers seem to process “women's” as a possessive noun establishing a relationship between “women” and “clothes”, non-native speakers believe that the clitic would be omitted in “women's” as “women” is considered by them a premodifying attributive noun functioning as an adjective – e.g. “clothes which have been designed for women”. There are other constructions which seem to be problematic such as “women's range”, “women's clothing”, “women's clothes magazine”.
The question is: if the clothes have been designed for women and they do not belong to them yet, could we say "women's clothes"? Wouldn't "women clothes" be more suitable here? If not, why?
In "Find out what women's clothes were like in the 19th century", I believe "women's clothes" is the right construction here as those were the clothes worn or used by women in the 19th century. Any thoughts on this?
we use the plural possessive form in such cases when the 'possessor' is humanif only it were that simple: cow's milk, goat's cheese, lamb's wool (also lambswool though) and sheep's clothing. Each one a creature, and all these expressions can be written with the possessive apostrophe. In English there is never a hard and fast rule. Never! And times change, so one day we will see women clothes being advertised.