Check out this video for the full conjugation of haben in the most important tenses:

Why is this verb important?

First of all, haben can be used as a full verb, like any other verb.

Example:
Ich habe 2 Arme
I have got 2 arms

Ich habe ein Haus
I have got a house

Ich habe ein Auto
I have got a car

In this case, ‘haben’ indicates some kind of possession. You could also say

Ich besitzte ein Auto
I own a car

This function of haben is easy to understand and there is nothing special about it. But there’s another function which is far more important because it concerns almost all other German verbs out there. It’s the function of ‘haben’ as an auxiliary verb. You need the konjugation of haben in the present tense in order to build the perfect tense of most other German verbs.

Some examples:

Ich habe geschrieben
Ich habe gelesen
Ich habe gewonnen
Ich habe verloren

As you can easily see, the use of ‘haben’ as an auxiliary verb is very similar to the use of ‘to have’ or avoir in French, avere in Italian or haber in Spanish.

Please note: If haben is used in order to build the perfect tense of another action verb like to read, to write, etc, the action verb doesn’t conjugate but it’s used in its participle form.

ich habe geschrieben
du hast geschrieben
er hat geschrieben
wir haben geschrieben
ihr habt geschrieben
sie haben geschrieben

If you are only just beginning to learn German you can skip the rest of this video and continue with the verb ‘sein’. If you stay with me for another minute, you will learn that the past tense konjugation of haben is used in order to build the past perfect tense. This is not quite as important as the perfect tense but you will still find these forms a lot, especially in books and written text.

Let’s use the same example that we just heard before and put it into the past perfect tense – that tense is called Plusquamperfekt in German and as I just said before – you might as well ignore this for the moment. But if you see it written in some book, you know what this is all about.

ich hatte geschrieben
du hattest geschrieben
er hatte geschrieben
wir hatten geschrieben
ihr hattet geschrieben
sie hatten geschrieben