Pronomen.
Words that replace nouns.

A pronoun stands in for a noun that has already been named, so the conversation does not repeat itself. Instead of derMann three times in a row, German says er. But a pronoun is not just one word with one job. Like an article, it changes its form depending on the case, and the case depends on what the pronoun is doing in the sentence → subject, direct object, or recipient.

One person, three sets of forms

Every personal pronoun has a Nominativ form for the subject, an Akkusativ form for the direct object, and a Dativ form for the recipient. The three forms can look completely different from each other, so each one has to be learned on its own.

Person	Nominativ	Akkusativ	Dativ
I / me	ich	mich	mir
you (informal)	du	dich	dir
he / him	er	ihn	ihm
she / her	sie	sie	ihr
it	es	es	ihm
we / us	wir	uns	uns
you all (informal)	ihr	euch	euch
they / you (formal)	sie · Sie	sie · Sie	ihnen · Ihnen

A few rows repeat themselves, sie and sie look identical, and so do es and es. The verb and the rest of the sentence usually make the role clear even when the pronoun alone does not.

Each set in full, with every example: Personal pronouns. The Nominativ set. and Personal pronouns. The Akkusativ set. One more pronoun type worth knowing: Possessive pronouns. Whose is it?

A pronoun keeps the noun's gender, not its meaning

When a pronoun replaces a noun, it takes over that noun's gender and number, even if the pronoun's English translation suggests something different. derTisch is masculine, so it becomes er, never es, even though "the table" is an "it" in English.

Noun	Gender	Becomes
derTisch	masculine	er
dieLampe	feminine	sie
dasBuch	neuter	es
dieBücher	plural	sie

In a sentence → DerTisch ist alt. Er steht da. (The table is old. It stands there.) DasBuch ist interessant. Ich lesees gerade. (The book is interesting. I am reading it right now.) The gender travels with the noun into the pronoun, the case depends on the new role the pronoun plays in its own sentence.

Question words ask for the right pronoun

Each case has its own question word, and the answer to that question is always a pronoun in the matching case. Asking the right question is the fastest way to find the case a pronoun should be in.

Question	Case	Finds	Example answer
wer?	Nominativ	the subject	Sie fragt.
wen?	Akkusativ	the direct object	Ich seheihn.
wem?	Dativ	the recipient	Ich helfeihr.
wessen?	Genitiv	the owner	Das istdieTasche desMannes.

Each question word in full: wer? The Nominativ question word., wen? The Akkusativ question word., wem? The Dativ question word., and wessen? The Genitiv question word.

Where pronouns sit in a sentence

When a sentence has both a recipient and a thing being given, the recipient normally comes first. But pronouns jump the queue. A pronoun moves earlier in the sentence than a full noun phrase, regardless of its case.

Sentence	Order
Ich gebemeinem BruderdasBuch.	two noun phrases → Dativ before Akkusativ
Ich gebeihmdasBuch.	Dativ pronoun before Akkusativ noun phrase
Ich gebeesihm.	both pronouns → Akkusativ before Dativ, the order flips

The rule in short: between two noun phrases, Dativ comes first. Between two pronouns, Akkusativ comes first. And a pronoun always comes before a noun phrase, no matter which case either one is in.