Well, my approach simply would be to do it the way most of us learnt BASIC back in 198x. We read the manuals of our computers. For example the C64 manual (less than 100 pages) or the Dragon manual
. The world was not so complicated back then and manuals could be read within minutes to hours.
Well out of the top of my head:
Single quotes do have no meaning in BASIC (at least in that kind of BASIC). It is just an ASCII-character like any letter. It never came to my mind to write something like PRINT 'HELLO WORLD'.
The concept of escaping characters was unknown to me until I started with C. If I needed an ESCAPE or a non-printable character, for example a printer control command, i would use CHR$(xxx), like PRINT CHR$(27)+CHR$(66). Same for double quotes (CHR$(34))
Strings are concatenated with "+" (PRINT "HALLO"+CHR$(20)+"WORLD").
Strings and/or Variables are printed with a TAB in between if you type a comma "," (PRINT "HALLO",A);
Strings and/or Variables are printed with a SPACE in between if you type a semicolon ";" (PRINT "HALLO";A);
Same for comma and semi-colon at the end of the line.
Leaving out the closing double quotes at the end of the command line was not "punished". New line, new context.
I think that are 95% of the rules. Really simple. Did I forget something?