“告诉”真的等于tell吗？to tell lie(s)----"说谎“，而不是”告诉谎“。 英语的tell, say, speak, talk, talk about, discuss....等等等等，和汉语的”说、讲、道、谓、述、告诉、讨论、述说。。。“等等等等，没有一个是可以真正相等的。 大家要改变这种"讨论＝tell”、”谈论＝talk about“这样的观念或思维方式。

告诉———tell example: 他告诉我...... He tells me blah blash 说———speak,say example: 他说: ...... he says:...... 谈论———talk about example: 他在谈论着什么 he is talking about something. 说说 is more informal. The meaning has to depend on passage.

1、The word 告诉 in Chinese is usually the same as the word“tell” in English. e.g. What I have been told is that.... （我被告诉……） or Can you tell me something about the Gravitational Wave?（你能告诉我一些关于引力波的东西吗？） 2、说 is used more widely which is more similar to the word"say". e.g. He said he had settled in a new city（他说他已经定居在一个新的城市） “ So incrediblely smelly it is.“he says.(“这也太臭了吧！”他说。） So when you express" tell someone something" you should say 告诉someone something, when you express "someone says that...." you say someone 说..... 3、说说 is informal usually used in conversations between friends. When you hear some stirring news/ or a new plan ,idea and something like that put forward by your friends or partners/ or anecdotes you interested in, you can say 说说看（it is an idiomatic phrase in Chinese） And sometimes even when you actually don't interested in your friends topic,for politeness, you say 说说看吧. 4、 谈论 means "talk with sb“ e.g. I just talked with Mary about the new manager. (我刚才和Mary谈论着新来的经理。）

English correction: You need an object. To tell SOMEONE about something. Example: I told him about Mary's accident. We cannot say "I told about Mary's accident."

告诉 = tell 说 = say 说说 I can't really think of an exact english equivalent for this, but repetition of an action verb is usually used to make the action seem to be done with more effort. So 说 means just "say" but 说说 is more like "talk about" or "discuss", for example 说说你的意见 (talk about / discuss your opinion). It's quite common in Mandarin. The long version actually has 一 in the middle, for example 说一说 or 看一看. 谈论 = discuss (this means more than just "talk". It suggests that the discussion has arguments/theories/etc.)