Wissen, Kennen

Wissen, Kennen

There are a number of other irregular verbs (besides haben, sein, and the modals) that are very frequently used and which you therefore have to learn.

One of them is wissen. Wissen means to know (in a factual way, as opposed to kennen, knowing by familiarity - see below!).

If you look at its Indo-European origin this verb is a "distant cousin" of the Latin verb vidi,which means I saw. And since one knows what one saw I saw is also I know. Funny! It also shows how knowledge in Western civilization privileges the sense of seeing - that is our eyes - as a source and proof of knowledge and truth.

Wissen functions often almost like a modal auxiliary. That means, as with the modal auxiliaries, Germans use the past tense of wissen frequently. You will need to memorize the stem vowel changes for the present singular and the past.

Notice that the personal endings are missing or abbreviated in the present singular! But like other verbs we have met in the simple past, a -t- before the ending is the sign of that tense.

The past participle of wissen is gewusst. That is a strange form, too: stem vowel change as in strong verbs, but 't' as ending as in weak verbs. You will see there is a whole group of verbs that are partly strong and partly weak. In its perfect forms wissen uses haben as auxiliary.

(Note: The "ß" is used with the singular present tense forms because it follows a dipthong; "ss" is used in the other forms because it follows a short vowel.)


Kennen and Wissen

There is another interesting aspect of wissen; namely, German distinguishes between two kinds of knowing.

One is based on sense perception or on trustworthy information, and in your mind a factual knowledge. Whenever one's knowledge has this form one uses wissen.

However, there is another form of knowledge based on direct (or indirect) acquaintance or familiarity with a place or a person. Whenever you speak about a form of knowing based on acquaintance or familiarity you use the verb kennen.

Examples:

• Kennst du Jochen? Nein, ich weiß, wer er ist, aber ich kenne ihn nicht.
• Kennst du Jochen. Nicht richtig, ich kenne ihn nur über Andreas, aber ich weiß, was er macht.
• Weißt du seine Telefonnummer? Ich wusste sie einmal, aber jetzt weiß ich nur noch seine Adresse.
• Kennst du Berlin? Nein, ich kenne Berlin nur vor dem Fall der Mauer, und ich weiß, Berlin ist heute ganz anders.
• Ich weiß, es gibt ein Schloss in Heidelberg, aber ich kenne es nicht.