The Code Formatter page (Progress OpenEdge > Editor > Code Formatter) of the Editor preferences includes the following options in the Control Statements tab:

Keep 'IF...THEN' in one line This option puts the THEN keyword in the same line as IF. By default, this option is checked.
Keep 'THEN' in new line This option puts THEN in the new line.

This option is disabled by default as its parent condition is selected and they complement each other. To enable, uncheck the parent condition.
Keep 'ELSE IF' in one line This option puts the IF keyword in the same line as ELSE. By default, this option is checked.

Keep 'ELSE' and 'IF' in separate line

 This option puts ELSE and IF in two different lines.

This option is disabled by default as its parent condition is selected and they complement each other. To enable, uncheck the parent condition.

Keep simple 'IF...THEN' statement in same line

 This option puts simple IF...THEN statement in the same line.

Keep simple 'ELSE' statement in same line

 This option puts simple ELSE statement in the same line as ELSE keyword.
Note: Simple statement refers to just one statement which does not need to be covered by blocks.

When you select these options, the Preview pane displays how the control statements appear in the Editor.

Apply stores your changes to the current workspace configuration. Restore Defaults resets the preferences to the Progress Developer Studio for OpenEdge defaults.