1. Uraian yang di dalamnya ada koma (,) sehingga dengan penggunaan tanda koma dapat dibedakan masing-masing uraian yang berbeda.
Contoh:
- She has three children: David, aged 20; Mary, aged 17; and Peter, aged 8.
- Lutfi Budiarto, Cola manager; Pitra, a businessman; and Zaky, one of the best students.
2. Tanda titik koma digunakan untuk memperluas kalimat.
- It was a nice holiday; we enjoyed ourselves.
- It was easy; I didn't need any help.
3. Tanda titik koma digunakan sebelum frasa: as a result, therefore, however, so.
- She suddenly got ill; as a result, the plan to go to Bali was cancelled.
- I want to go abroad; therefore, I have to study hard.
- There were no delicious foods around; however, we had no choice.
4. Dipakai sebelum kata sambung jika kalimat-kalimat sudah mengandung koma.
- Last night, Mary, to my alarm, came to me angrily; but today, she looked happy.
- The house looked badly neglected--the floors were dirty, and the ceilings full of spider web; but when I came back to the house the next day, it was, to my surprise, clean and tidy.