The expression 'ก่อนที่จะ (gɔ̀n thîi jà)' is equivalent to the English 'before'. It is used to describe an action that takes place before another action or event. The action that happens first is typically followed by 'ก่อนที่จะ' and the action that happens later is expressed after the term 'จะ'. This structure helps to order events in a timeline and establish the sequence of actions.