Language difficulties always happen to non-native speakers (foreigners). Moreover, not all people can speak English. Let's say, in one situation where an old lady comes to you and ask about something. Then there is where the language difficulty happens.
Old lady: 你好..!@#$%^& (in Chinese language and you understand only 你好)
*你好 (ni hao | ㄋㄧˇ ㄏㄠˇ) = is used as greetings, can also mean "How are you?"
To reply 你好 (ni hao | ㄋㄧˇ ㄏㄠˇ) is 你好 (ni hao | ㄋㄧˇ ㄏㄠˇ) itself.
Here are some other replies that can be used:
*You can add Sorry = 對不起 (dui bu qi | ㄉㄨㄟˋ ㄅㄨˋ ㄑㄧˇ) in front of the sentence if necessary.
Can you speak English? = 你會說英文嗎? (ni hui shuo yingwen ma? | ㄋㄧˇ ㄏㄨㄟˋ ㄕㄨㄛ 一ㄥ ㄨㄣˊ ㄇㄚ?)
*English = 英文 (yingwen | 一ㄥ ㄨㄣˊ)
I don't understand Chinese = 我不懂中文 (wo bu dong zhongwen | ㄨㄛˇ ㄅㄨˋ ㄉㄨㄥˇ ㄓㄨㄥ ㄨㄣˊ)
*Chinese = 中文 (zhongwen | ㄓㄨㄥ ㄨㄣˊ)
I don't understand = 我不懂 (wo bu dong | ㄨㄛˇ ㄅㄨˋ ㄉㄨㄥˇ)
*不 (bu | ㄅㄨˋ) = no (negative)
*懂 (dong | ㄉㄨㄥˇ) = to understand
Can you write it down for me? = 可以寫給我嗎? (keyi xie gei wo ma? | ㄎㄜˇ ㄧˇ ㄒㄧㄝˇ ㄍㄟˇ ㄨㄛˇ ㄇㄚ?)
*write = 寫 (xie | ㄒㄧㄝˇ)
Can you say it one more time? = 可以再說一次嗎? (keyi zai shuo yici ma? | ㄎㄜˇ ㄧˇ ㄗㄞˋ ㄕㄨㄛ 一 ㄘˋ ㄇㄚ?)
*說 (shuo | ㄕㄨㄛ) = to say, to speak
*one more time = 再一次 (zai yi ci | ㄗㄞˋ 一 ㄘˋ)