Thought exists without language, does it not? How can dogs dream of sticks and walks and chasing squirrels? Can't cats see a high place and think about how to reach it, those aren't thoughts?

The word Language comes from the word for tongue, language therefore is grounded in human ability to make complex thoughts borne out in simplistic squishy tongue air sounds.

We could extend language beyond tongues though, if we think of binary or rust or gobbledygook made up languages impossible to speak. Those still Express thoughts, though they be divorced from tongues.

So, IMO, thoughts are broader than language, which can come close to thought but can not adequately encapsulate the color red, a beautiful piece of music, or a cat's devilish designs.