Did the prehistoric Neanderthals make any tools and art or develop any complex language and culture?

No, prehistoric Neanderthals did not make any significant tools and art or develop any complex language.

They therefore did not have a culture that we know of.

Even though they did have brains as large as ours and lived concurrently with Homo sapiens at a time when humans were making tools, painting caves, and traveling the sea, the Neanderthals were apparently a pretty dim cousin; hence the derogatory term.

There’s no known art from them, and no evidence of technological advancement, leaving a strong suspicion that these strong silent types were literally that.

They may have never even developed a language.

The Neanderthals died out about 35,000 years ago. Homo sapiens aren’t due to go extinct for at least another decade or two.