Can an articulated thought occur to an individual's mind without a language or object to inspire it? People who has been deaf since birth, what language they used to think? People who are blind from birth, while dreaming in sleep, what projections would they see?
I don't think language are significantly different. When I think to say a sentence, just before I say it the sentence comes to me as an imagined experience. I imagine a sentence that I could say. Don't be misled by the root meaning of "image," the process is the same. It is still an idea that is assembled subconsciously. I experience the idea to say the sentence and I judge whether to say it or not. Even the judgment whether to say it itself is assembled from further subconscious ideations. There is no clear distinction between what happens in verbal thought and what goes on in visual imagining. At times visual imagining can even be more active and conscious than some verbal thought.
Words are not merely for communication, but they also serve the essential purpose of internal dialogue, contemplation, and articulation of non-verbal mental processes. Without words, we would not have the advanced level of self-awareness that we do, something that separates us quite significantly from other animals.
Linguistic semantics may be relevant here, but not semantics in general. If someone simply imagines or conceives of some image or sensation, no, that would not be considered a thought. But if one has some cognitive linguistic construct—even if it is not a standard/verbal language as in the case of a from-birth deaf person—then that would qualify as thought, as it is a function of linguistic semantics. So it's not the signs imagined and their manipulation that makes a thought, but the linguistic analysis and creation of images that makes a thought.