How to use the conjunctive words such as "うえに","しかも", "ですが" and "けれど"

Evaluation words can be classified into 2 types, positive and negative.
Examples are as follows:

Positive Evaluation

• light
• warm
• tough
• simple
• easy
• reasonable

Negative Evaluation

• heavy
• cold
• fragile
• complicated
• difficult
• expensive

(Positive/Negative classification can be inverted(interchanged) depends on specific situation. Classifications shown above are just one of the examples)

If we use two evaluation words at one time, we usually concatenate those words with conjunctions such as “and, but, or”.

In English, if someone says two evaluation words at one time, and both of them are positive or negative, he could use conjunctive word “and”.
Ex: This car is expensive and fragile.
Explanation of this book is easy to understand and useful.

In contrast, if someone says two evaluation words of opposite evaluation at one time, he could use conjunctive word “but”.
Ex: This car is expensive but tough.
Explanation of this book is difficult to understand but useful.

In Japanese, there are several words that represent the meaning of “and”, “but”.
Ex: “うえに”, ”しかも”, “かつ” for “and”
“ですが”, “けれど” for “but”

This car is expensive and fragile.
この車は、高価な　うえに　壊れやすいのです。
Explanation of this book is easy to understand and useful.
この本の説明は、わかりやすくて　しかも　役に立ちます。

This car is expensive but tough.
この車は、高価ですが、壊れにくいのです。
Explanation of this book is difficult to understand but useful.
この本の説明はわかりにくいけれど、役に立ちます。

I hope this helps .