What is the sentence structure for Japanese?

Answer 1

The order is usually - Subject Object Verb
I Eat Fish becomes "I Fish Eat"

There are particles (very short words) tacked after each thing in the sentence that tell you whether it is subject object or whatever.

eg. wa = subject o= object
so I eat fish becomse "I-wa Fish-o Eat"

Anything that is not necessary to understand the sentence is left out so...
I Eat Fish becomes - "Fish-o Eat" (It's generally fairly obvious that you are talking about yourself)

Although I said the sentence order is generally SOV - the particles make it possible to understand the sentence even if you say it in a different way, so actually you put the things you want to emphasise at the beginning.

So if you were asked what you were doing and you wanted to say that you were eating, but thought they might like to know it was fish you were eating too, then you would say -
"Eat Fish-o"

Does that make it clear as mud?

Answer 2

Depends on whether you're in the earthquake zone or not...