Sentence with demonstrative without explicit subject - de required?

Question

I am unable to understand, whether the sentences below require the particle de?

Zhè ge hěn hào chī (literally "this piece of food delicious". I guess there is no "de" in the end, although it is an adjective in this sentence, modifying the measure word "ge").

zhè zhī hēi de (This cat is black. For some reason, there is the "de" but I cannot see why).

zhè Ben Shu hěn hào (This book is good. Here again, the "de" is missing. When I tried to verify with google translate, it used 是 but I guess that is not correct.)

So is it because those are one-syllable adjectives? I have heard that often in that case, the "de" particle is skipped.

Answer 1

Always check the full context of your original sentence. 的 use to indicate items/things/action explicitly.

你说的是那一只猫 ？ ： Which cat your are talking about
zhè zhī hēi de 这只黑的 ：This black one (pointing to specific black cat among many black cats)
你要那一支蓝笔 ？ ： Which blue pen you need? 
这支蓝的,(or simply 这支) ： This one , for specific. (or simply "This one")

What happens when you say : zhè zhī hēi 这只黑

This always follow after an inquiry for comparative items, with affirmative answer.

Q ：I want the darkest black cat 我要最黑的黑猫
A : This is the darkest(or simply, "this one")   这只黑 (这只）
Q : Give me the sweetest watermelon 我要最甜的西瓜
A : This one 这个甜  

Answer 2

这个很好吃。

一般语气，可以不加'的'。
若要加强语气，加'的'，而且念重一点。

这是黒的。
这猫是黒色的。

通常要加'的'。

这本书很好。

和第一例一様，平常可省略；加强语气时，加'的'。

Answer 3

1. 有时候会在形容词后面加“的”，没什么实际意义。

比如：

诶，我和你讲，这瓜超甜的。

（Hey, I'd like to tell you that this melon is so sweet.）

2. 有时候“的”的后面省略了一些词，需要根据语境（context）补充。

比如：

这支笔是谁的？（谁的笔）

我的（我的笔）

٩( 'ω' )و May you understand what I said.