You can recognize an irregular verb only when you look at the changes in its stem in the 2nd (=du) and 3rd (=er, es, sie) person singular.

ACHTUNG: Other than that there is NO WAY to know whether a verb is irregular or not. You will have to learn by heart which verbs are irregular. But, don't worry about this at all. Once you reach the lesson about the past tense, you'll get to know a technique that will help you to do that very easily.

I have marked the stems red here where it matters. Let's take a look at a few examples. Take a look at the verbs fahren - to drive, lesen - to read and nehmen - to take:

The lovely thing about German irregular verbs is that they are very often pretty regular in their irregularity. Take a look at the three examples from before and see whether you understand the following:

1. There are only two kind of changes in the stem:
   The letter a changes to ä
   The letter e adds/changes to an I
2. Any change appears only in the du- and es-forms.
3. The plural is always regular
4. Some verbs change more than one letter > nimmt
5. The du-form loses the "s" of the ending after a root-s
   du liest, du isst, du heißt causing the du- and es-forms to look alike

The steps above provide you with a generally applicable set of rules that will get you started. In the following, we will take a look at some specialties, especially the verb sein > to be and some of the more irregular verbs.

*For reasons of clarity, I won‘t write er/es/sie or sie/Sie anymore in such overviews. Instead you'll only always see "es" for the 3rd persons singular and "sie" for the 3rd persons plural.*

More irregular verbs

There is no rule to teach here. I just want to show you some of the more irregular verbs in the present tense. These are widely used and you should master them one day. But for now simply try to follow my notes as good as possible. Don't try to learn these by heart here. That'd be a waste of your precious time.

Note that, with the sole exception of sein, the plural is always regular! Take a look at the following verbs: sein - to be, haben - to have, werden - to become, wissen - to know, treten - to kick:

• The verb to be is the most irregular verb in German.
• haben changes in a peculiar way: it leaves out the root-b (hast instead of the expected habst) in the du and es forms. Otherwise it is totally normal.
• werden shows the usual change from e to i in the du and es forms. It also skips the t-ending with es instead of simply adding another e (which would result in the non-existent wirdet).
• wissen is one of the few verbs also changing the ich-form. It has no ending in the ich-form, plus it changes the other way round from i > ei.
• There are no such verb-forms as ich weiße, or er/es/sie weißt.
• Treten: du and es double the t and avoids the extra e.