的
de
的 is a tag you tie onto the thing
The picture A hand tying a small tag onto an object. Everything before 的 is what is written on that tag. After 的 comes a thing; after 地 comes an action. 慢慢的 is a label on an object, 慢慢地 is an outfit on a verb.
Where the picture shows up in 的
-
the tag says whose
这是我的工牌。
zhè shì wǒ de gōngpái
This is my staff badge.
A small tag knotted onto the badge lanyard, with mine written on it.
-
a whole clause on the tag
昨天来的那个人是谁？
zuótiān lái de nàge rén shì shéi
Who was that person who came yesterday?
The words came yesterday copied onto a tag and hung from that person's collar.
-
the tag alone, thing left out
我要热的，不要冰的。
wǒ yào rè de, búyào bīng de
I will take a hot one, not an iced one.
The cup has been cleared away and only the tag reading hot is left in your hand.
-
the tag says what it is made of
这个箱子是塑料的。
zhège xiāngzi shì sùliào de
This box is plastic.
A material tag stamped plastic stuck on the side of the box.
-
a tag on the whole sentence
别担心，会好的。
bié dānxīn, huì hǎo de
Do not worry, it will be fine.
A sheet reading it will be fine pressed against the wall and pinned down with a tack.
Sentence-final 的 nails down that this is simply how things are. It has nothing to do with possession.
All of it in one picture
The tag on the lanyard says whose it is; the words hung from the collar are a whole clause riding on the tag. The tag left in your hand with the cup gone shows the tag alone can do the work, the stamp on the box says what it is made of, and the pinned sheet is a tag put on the entire sentence. All five are the same gesture: tying what came before onto what comes after. So when you meet 的, do not reach for of, look instead for what it is tying a label to.