passive in noun modifier


I understand the use and structure of a noun modifier using standard masu
plain past form, eg たなかさんが かったすしは、... etc. etc. The sushi that Tanaka
bought... etc. Now it's noun modifier with subject ga, masu verb in plain
past, modifying the noun, sushi.

I get that in passive it's the object that's being highlighted, that now forms
the subject. And I get direct and indirect passive sentences. No worries.

But what are the rules for using passive to modify a noun and why and when is
it preferred over plain masu form?

  1. わたしが たべた Pizzaは きのうのばん ともだちに つかいました。 ok all good.

  2. たべられた Pizza は おいしかったです。/ or should I use a noun to finish sentence, よくham and pineapple です、

I am not really understanding why No2 in passive, is wrong.




It's not about logic, but is more to do with the availability of other
expressions.

> **1** わたしが たべた ピザは おいしかったです。  
>  **2** たべられた ピザは おいしかったです。

The #1 straightforwardly makes sense.  
The #2 is hard to process what it's saying. :) When you want to say an unusual
thing and express the pizza as something being eaten, we would try to make it
clearer and say something like

> **3** わたしに たべられてしまった ピザは おいしかったです。

But again, this is an unusual thing to say.

When you want to say 'a pizza that you were **_able to_** eat,' this could be:

> **4** （やっと）わたしが ありつけた ピザは （それでも）おいしかったです,

In other words, we usually want more expressions, modifiers, adverbs in the
sentence. However, if you say わたしに instead of わたしが, it becomes more natural
even without additional modifiers:

> **5** わたしに たべられた ピザは おいしかったです。

In this way, it can naturally sound like talking about what you've been
**_able to_** eat than what has been eaten by you. The reason could be your
health condition.

