During my time learning Chinese, I've heard two distinct word orders when referencing the time at which something will occur. For example, I was taught to say 今天我想吃早饭 to talk about 今天, 明天, etc, but I was taught to say 我想八点钟吃早饭 when speaking about a specific time, which seems a rather different word order.
What are the rules surrounding the word order when talking about time in this context? Are both ways acceptable (that is, would 八点钟我想吃早饭 and 我想今天吃早饭 also be okay)?
I think it's just the same when it is in english:
今天我想吃早饭 - Today I want to have breakfast
我想八点钟吃早饭 - I want to have breakfast at eight
我想今天吃早饭 - I want to have breakfast today
八点钟我想吃早饭 - At eight, I want to have breakfast
All these sentence make sense and are acceptable.
I'm not an expert in sentence structure, but I believe
我想今天吃
has a more focus on the necessity of eating something today, where
今天我想吃
does not have such focus.
As for the case of specific timing, it works the same way. If you add 在 (at) to the sentence
我想(在)八点钟吃早饭
then you are stressing that you want to eat breakfast at 8 o'clock. On the other hand,
(在)八点钟我想吃早饭
does not have such focus. But I have never heard people talk like this way though.
