Hi Hui The previous answers have all highlighted different problems with the 3 sentences. My interpretation is this: 1) It is time that we went home. It's ok, except that you would only normally encounter this sentence in reported/recorded speech and the 'that' would normally be dropped for brevity and clarity: "It's time we went home." This effectively means that the appropriate moment has arrived when we should go. 2) It is time that we should go home. Not correct. To be reasonable English, you will need to replace 'it is time' with 'now': Either: "Now we should go home", or "We should go home now". If 'now' is at the beginning of the sentence, the emphasis is that going home is the next thing we should do. If it is at the end of the sentence, the emphasis is that the time to go is right now, at this moment. 3) It is time that we go home. The tense of the verb 'to go' is not correct here. Use it like this and it is OK: "It is time to go home." or "It is time for us to go home." So, once the English is corrected, the answer to your question is that all three have slightly different meanings. 1) is slightly less forceful than 3), but probably interchangeable with it. 2) has one of two slightly different meanings, depending on word order. 3) is a clear and unambiguous statement of fact (the time to go is now).

辉, The sentences are all correct. It is time... It is high time... It is about time... All three of the above expressions can be used to complain or criticize. The use of "that" is alway optional in English. It's use is correct here, though dropping it is often the preferred syle. I imagine "that" is being used in these sentences to make a point about English grammar. 1) It is time that we went home....It is time + past subjunctive (unreal past). We ought to go home now. You may not go home after saying this but you want to! 2) It is time that we should go home......This is a way to say it avoiding the subjunctive. You can also avoid the subjunctive by saying: It is time for us to go home. 3) It is time that we go home.....It is time + present subjunctive Present subjunctive is often used in American English after demands or suggestions or recommendations. This is a polite suggestion for future action. And one more 4) It is time that we were going home. Similar to 1) using the past subjunctive but more polite.

The third sentence is 80% correct...

Also, the second sentence would just be "We should go home (now)." Putting in "that" isn't necessarily wrong, but it's not something you would normally say. It's better just to not use it. Other than that yes, they mean the same thing.

They're all wrong. You have to leave out the "that" in all three of them.