Not all the time. I can think about abstract concepts with no language needed whatsoever. Like when I'm working on my car. I don't need to think to myself "Ah this bolt is the 10mm one that went on the steering pump", I just recognize it and put it on.
Programming is another area like that. I just think about a particular concept itself. How the data will flow, what a function will do to it, etc. It doesn't need to be described in my head with language to know it and understand it. LLMs cannot do that.
A toddler doesn't need to understand language to build a cool house out of Lego.