Pronouns

English pronouns generally have different forms between subject & object:

Subject	Object
I	Me
Thou	Thee
He	Him
She	Her
It	It
We	Us
You	You
They	Them

Notes:
The second person singular (thou/thee) is now outdated in English but still very common in other languages.
Third person singular distinguishes between masculine, feminine & neutral, whereas the plural does not.
"We" is ambiguous - it includes "I", but does it include or exclude "You"?
"It" & "You" manage perfectly without specific object forms.
French & German complicate things even more.

I think a super-simple language can get by with only four pronouns, for example:

Lingo Pronoun	Replaces English
mii	I - Me
yii	Thou - Thee - You
zii	He - Him - She - Her - It - They - Them
wii	We - Us

Genetives, datives, reflexives etc can be handled by affixes, to be dealt with separately.