mixed syntax control structures generating syntax errors

i'm refactoring php formula detected certain nested combinations

if () :

and

if () {

generate syntax errors. i customarily brew two, nonetheless i revisit syntax checks i'm minute formula i kept removing syntax blunder since this.

example - generates syntax error:

if ( $test == 1 ) :
  ( $test2 == 'a' ) {
    ( $test3 == 'a' ) {
    } else {
    }
  }
else :
  relate 'test2';
endif;

example - does beget syntax error:

if ( $test == 1 ) :
  ( $test2 == 'a' ) :
    ( $test3 == 'a' ) :
    else :
    endif;
  endif;
else :
  relate 'test2';
endif;

could someone greatfully explain me since initial retard formula generating an error?

code1