Why does the grammar structure for "I think [statement]" work the way it does?


In my Japanese class, I've been taught that the structure for "to think" is
"～と思う", but no explanation was given for why this is the way it is.

For instance:

> 日本の中で食べ物は高いと思う。

Obviously the first part of the sentence reads, "In Japan, food is expensive"
- but the last part doesn't seem to make sense in-context. Maybe it's because
I haven't seen grammar structures with multiple verbs before.

> さけおさんは酒を飲まないと思う。

This sentence has effectively the same structure as above, but the ending of
the sentence just... doesn't sound right. It doesn't make logical sense given
the grammar rules that I know so far.

How should I break this sentence down so I can hear this intuitively? Is the
form "～と思う" part of a larger type of grammar that I am not yet aware of?

Additionally, I've never seen the particle と used this way before. What does
it mean here?




I'm not sure what's confusing you but...  

Japanese often omits the subject when it's obvious from the context, so your
first sentence can be read as:

> 『日本の中で食べ物は高い』と(私は)思う。  
>  (I think that food is expensive in Japan.)

The と is the case particle as a quotative marker.  
Likewise, your second sentence can be read as:  

> 『さけおさんは酒を飲まない』と(私は)思う。  
>  (I think that Sakeo-san doesn't drink alcohol.)




I'm not sure what's confusing you but...  

Japanese often omits the subject when it's obvious from the context, so your
first sentence can be read as:

> 『日本の中で食べ物は高い』と(私は)思う。  
>  (I think that food is expensive in Japan.)

The と is the case particle as a quotative marker.  
Likewise, your second sentence can be read as:  

> 『さけおさんは酒を飲まない』と(私は)思う。  
>  (I think that Sakeo-san doesn't drink alcohol.)

