[1] Mainly due to begin..end blocks, curly braces or indentation (as in Python)
My days of fiddling with writing parsers are long ago (https://www.codeproject.com/Articles/7035/A-Java-Language-ID...) but if I remember correctly most languages aim for at most a LL(2) grammar, meaning they are designed so the parser doesn't have to peek more than two tokens ahead before being able to make a correct determination.
a * b;
Is either: a times b if a is a var, or declare a varible b with type a. If a is a typedef.
Also:
some_type b = {a, b, c, d};
Is only valid if some_type is an array or a struct. Which is possibly defined elsewhere in the source.
(I tend to see this syntax in some code bases (some_type) { a, b, c, d }, which is a bit better).
CPP (Pre-processor) aside, C is not context free due to typedef making identifiers ambiguous. Also if-then-else? Since C++ templates are turing-complete, the grammar is probably unrestricted.
Python is not context free due to
if ...:
stmt1
if ...:
stmt2
stmt3