Dialogues

1. 喂，刘经理在家吗？Wéi, Liú jīnglǐ zài jiā ma?
Hello. Is manager Liu in?
Wei2 is hello. Liu2 is a surname. And "jing1li3" means manager. So put together "liu2 jing1li3", manager 4 is a preposition word. It means "at". home in Chinese is: jia1.

2. 他什么时候回来？Tā shénme shíhou huílai?
When would he be back?
Manager Liu is not at home now. If you want to ask: "When would he be back?" in Chinese you can say it in this way:"ta1 shen2me shi2hou hui2lai". ta1 means "he". shen2me shi2hou means what time. Shen2me is what and shi2hou is time. hui2lai is to come back.

3. 请他给我回个电话。Qǐng tā gěi wǒ huí gè diànhuà.
Please tell him to call me back.
The other also doesn't know when would manager Liu be back either. how would the Chinese say: Please tell Manager Liu and let him call me back. You can say: qing3 ta1 gei3 wo3 hui2 ge4 dian4hua4."qing3" means please. "ta1" here means he."gei3" is to give. "wo3" means I. "hui2 ge4 dian4hua4", to call someone back."hui2" literally means to return,ge4 here is a measure word for phone call."dian4hua4" means telephone.