予定を変更する

The word '予定' (yotei) is a noun meaning 'schedule,' 'plan,' or 'arrangement.' It is composed of two kanji: '予' (yo), meaning 'in advance' or 'pre-,' and '定' (tei), meaning 'decide,' 'determine,' or 'fix.' So, '予定' literally means 'something decided in advance.' '変更' (henkō) is a noun meaning 'change,' 'alteration,' or 'modification.' It is also composed of two kanji: '変' (hen), meaning 'unusual,' 'change,' or 'strange,' and '更' (kō), meaning 'renew,' 'update,' or 'change.' Together, '変更' conveys the idea of making something different or renewing its state. 'する' (suru) is a common irregular verb meaning 'to do' or 'to make.' When combined with a noun like '変更,' it forms a verbal phrase, meaning 'to do a change' or 'to make a change.' The particle 'を' (o) is an object marker, indicating that '予定' (schedule) is the direct object of the verb phrase '変更する' (to change). Therefore, '予定を変更する' literally translates to 'to change the schedule,' and its meaning of 'to alter a pre-arranged schedule or activity' is a direct reflection of the individual meanings of its constituent parts and their grammatical arrangement.