Please add a comma after the greeting line before sending the email to the client.

寄電子郵件給客戶前，請在問候語後面加上逗號。

The contract amount was misread because someone left out a comma in the figure.

合約金額被看錯了，因為有人在數字中漏掉了一個逗號。

Our shipping form requires a comma between the city name and the postal code.

我們的出貨表格要求在城市名稱和郵遞區號之間加逗號。