In the reply to 你是什么时候去上班的?, what does the 的 in 我是九点去上班的 mean? I think that without the 的, the sentence makes sense in and of itself, right?
And the meaning is that I start to work at 9:00 am...., right?
These other answers are good, but they're missing the crucial element, which is why you have the 的 in that sentence. It's because 是, roughly translated into English as is, am, are, is a linking verb that is expecting a noun. If you said 我是九点去上班 that would essentially mean, I am go to work at nine. Which, of course, doesn't make sense.
However, 的 takes whatever is before it and turns it into an adjective, thus making "go to work at nine" an adjective. You're probably thinking, "Where's the noun, then?" Well, the noun is implied. That means that 我是九点去上班的 translates into I am a go-to-work-at-nine-type of (implied noun), or rather, I am a person who goes to work at nine.
Make sense? It sounds a little convoluted, but that's what's going on.
Here it's a 是 + 的 combo sandwich, where 是 + 的 emphasizes what's in the middle.
我是九点去上班 doesn't sound right - because here 是 and 的 are like bookends with one bookend missing.
You could however just say 我九点去上班 which would sound absolutely fine.
verb (verb phase) + 的 is like a noun, but may have different meaning. for example:
吃 (verb, eat) 的: something that could be eaten
喝水 (verb phase, drink water) 的: somebody who is drinking water / drank water
– gcd0318 Dec 22 '15 at 05:11Although I am not good at English,but as a Chinese,I have the confidence that "的" is the symbol of the adjective.For example,"office" means ”机关“.it is a noun;"official" means "官方的“.It is a adjective which adds meaning of nouns;"officially" means "官方地"It is an adverb which adds information about the action.In this sentence"我是九点去上班的”,there is something omitted that all the Chinese will do it.The full sentence is"实际上,我是九点去上班的。" means "The true is(or the situation is)that I went to work at 9:00."With "的",makes the whole sentence become a adjective which adds information about the situation.It is a past tense or not,depends on the texts or conversations.In a similar way,"他是吃素的" can translate into "He's a vegetarian",because it means"The situation is that he eat vegetables only.(or he never eat meat)" .That is why this sentence can describes a personal eatting habits.It is for Lars Andren.
的 is really a hard word to learn
verb + objective + 的:people doing something
verb + 的:something that is done by verb, or something that could be done
Another example:
A: 你今天怎么没做饭啊?(Why didn't you cook today?) B: 哦,我是在外面吃的。(Oh, I ate outside.)
– Lifu Tang Mar 08 '15 at 22:05今天我是在学校就把作业做完了的。(past tense) 她是已经有工作的。(do-something-type of) 昨天他是在健身房洗澡的。(past tense) 你是经常失眠的么?(do-something-type of)
Context matters.
– Lifu Tang Dec 03 '15 at 19:24是……的can represent an emphasize of past truth. Plus, there is去which is rarely used in that "type" case.-妻子:你什么时候出门的?(Wife: When did you get out of the house?) -丈夫:我是九点去上班的。(Husband: It was nine when I was going to work.)
-领班:你是哪个班次的?(Head: Which shift are you on?) -工人:我是九点上班的。(Worker: I am on the nine-o-clock shift.)
– Jamesits Dec 04 '15 at 06:15今天我是在学校就把作业做完了的does imply past tense in that context, so could今天我在学校就把作业做完了. – musicnothing Dec 07 '15 at 15:55