What potential syntax errors could cause a "Parse error: syntax error, unexpected T_STRING" in PHP code?

A "Parse error: syntax error, unexpected T_STRING" in PHP code typically occurs when there is a syntax error involving a string literal. This could be due to missing quotes around a string, using the wrong type of quotes, or having a string that spans multiple lines without proper concatenation. To solve this issue, carefully check your code for any missing or incorrect quotes around strings.

// Incorrect code causing a parse error
echo Hello World!;

// Corrected code with quotes around the string
echo 'Hello World!';