The traditional answer was to use a BASIC dialect. Minimal syntax, minimal structure, simple imperative commands. A lot simpler than Pascal. I don’t know TCL very well, but its scope semantics may be confusing. I’d take a look at LOGO also.
I think the beauty of BASIC for teaching is that it's easy to "think like the computer," because the computer holds very little information other than the values of the variables that you used. For this reason things like loops are quite concrete.
Those who break past "the wall" and achieve any fluency at programming, can and will learn to start thinking in layered abstractions. And their programs will start to get bigger. Then it's time to move away from BASIC.
I moved to Pascal. Today, Python. But I agree with the above and about Python, that you are forced to handle abstractions, almost from the git-go. Perhaps what saves it is the ease of trying things, so if the functioning of a loop like "for i in range(10)" is confusing, just try it with a print() statement in there.
BASIC was also preferable on a timeshare machine. Waiting 10 seconds per line for a response seemed more tolerable than waiting 10 minutes for an entire program to compile and link.
Having learned Basic (Commodore as well as Qbasic), Pascal (not Delphi) and TCL in my youth, TCL is the only one I used in production. TCL is fairly simple to learn, it only takes a few concepts really, and it is quite a joy, if memory serves right. Of those I mentioned, it is the only one that I would touch again, for any reason, whether for fun or profit.
The only problem with BASIC is that it's kind of gross scaled up for medium-sized applications. It's downright charming at the Tiny-BASIC, VIC-20 BASIC, or even BASIC-52 level though.
LOGO has real depth, an elegant syntax, and there's an alternate universe where it has Python's niche as everyone's favorite scripting language. But it's effectively a toy language so there's nowhere to go from "learning".
Here's my hot take: before you teach anyone "the basics of programming", teach them how to enter formulas in a spreadsheet.
