そんなこと言うべきではないよ。って英語でなんて言うの？

"You should watch what you say." This is warning someone that what they say may be offensive or hurtful to someone. "That isn't a nice thing to say." This is very direct in saying that what they are saying isn't nice to say to someone else, you, or themselves.

The two sentences you see above are terrific ways to tell someone that you think what they said was not appropriate. In the second sentence you will see the expression uncalled-for. This expression means that something(normally a person's behavior or words) are pointless and inappropriate. This is an expression that is common in our everyday conversation and it would be a great addition to your vocabulary.

If someone says something that is offensive to you or others, there is no need to be polite to that person. You can use the imperative form: "Don't" + verb. Eg."Don't speak to me like that!" You may even go so far as to challenge the quality of this person's upbringing, as in the second example sentence. The response, and its level of severity, depends entirely on the situation, those involved, and the nature of what is being said.

Instead of repeating what they have said you can use the word 'things' to refer to the words you would like them not to say again.

Sometimes people say things without thinking or meaning to hurt anyones feelings but it does so you could tell them 'you shouldn't say things like that' or 'you must not say things like that' A nicer way to tell them is 'That's not a nice thing to say'

1. When something is appropriate, it is accepted, normal and/or right. So, to say that something was inappropriate, means that it was wrong, or it is seen as unacceptable. 2. When we advise people we use "should". Simply, we can use "Should + not" to advise people not to do a certain action.