Chinese sentence when only object is mentioned

Question

I am wondering is there any rules for sentence structure when only object is involved. For instance: 他的成绩一直是我们班最好的 (what rule is for this sentence) why in this case the object is not place in the end of the sentence following the SVO structure.

Thank you! Best wishes

Answer 1

Grammar books seem to split the 是……的 grammar construct into a whole bunch of cases (and here and here) using jargon like distinguishing words. I prefer to simplify, and think about this grammar construct as meaning:

X 是 Y 的
X (noun phrase) has the property Y (adjective phrase)

It's perhaps linguistically imprecise, but all we're really doing is applying some kind of adjective (described by Y) to some kind of noun (given by X).

So:

这是真的。
This has the property of being true.
This is true.

那辆车是红色的。
That car has the property of being red.
That car is red.

这个消息是昨天发布的。
This news has the property of being released yesterday.
This news was released yesterday.

我们是2011年认识的。
We have the property of having met in 2011.
We met in 2011.

我是坐飞机来的。
I have the property of coming by plane.
I'm coming by plane.

And finally...

他的成绩一直是我们班最好的。
His grades always have the property of being the best in our class.
His grades are always the best in our class.

Answer 2

Because no subject actually do something to object.

His grade is always the best among that of our class.

是 denote something is true. Something in back of 是(他的成绩) have this property written in front of 是(我们班最好的). So people understand 他的成绩是我们班最好的.

Finally add 一直 directly in back of 是 to denote frequency.

Answer 3

There is no 'object', only an equality.

他的...成绩...一直....是..我们..班...最好的
His results always are our class best (results)
His results/grades are always the best in our class.

Get rid of unnecessary words:

他的..成绩...是...最好的
His results are the best.

His grades = the best (grades)

Turn it around:

我们班成绩最好的是他