When I communicate with people who learn German as a foreign language I can often recognize that they have some difficulties with using the German verbs “kennen” and “wissen” correctly. Unfortunately, these two verbs have only one translation in English, which is “to know”. Although “wissen” suggest the meaning of having a firm knowledge and “kennen” rather means that you are only familiar or acquainted with something, both verbs do basically express the same idea. Which of these two verb you have to use does not only depend on its meaning but also on the sentence construction you will use.

In this post I would like to explain when and how to use one or the other verb. Let’s find out about that by asking ourselves “do we know”?

WISSEN

In German we use the verb “wissen” when we want to find out about a particular event or state. That is, when we ask, e.g “weißt du” (do you know) the following word has to be either an interrogative (question word) or a conjunction, e.g.

Here are some example sentences. I also give the possible answers to these question so that you can recognize how to use “wissen” in your responses:

Weißt du wann der Zug abfährt? – Do you know when the train is leaving? (Ja, ich weiß wann der Zug abfährt.)

Weiß sie wo ich wohne? – Does she know where I live? (Ja, sie weiß wo du wohnst.)

Weiß du wer das Buch geschrieben hat? – Do you know who wrote the book? (Ja, ich weiß wer das Buch geschrieben hat.)

Weiß du was das heißen soll? – Do you know what this should mean? (Ja, ich weiß was das heißen soll.)

Weißt du wie spät es ist?   – Do you know “how late it is” (what time it is)? (Ja, ich weiß wie spät es ist.)

Wissen sie ob er zur Party kommt? – Do they know if he is coming to the party? (Ja, sie wissen ob er zur Party kommt.)

Weiß er, dass sie geheiratet haben? – Does he know that they got married? (Ja, er weiß, dass sie geheiratet haben.)

In this type of sentences you cannot use the verb “kennen”. You can neither ask “Kennst du wann/wo/wer/wie/etc. …?” nor can you answer with “Ja, ich kenne wann/wo/wer/wie/etc. …”

KENNEN

In German we use the verb “kennen” when we ask or talk about a specific thing or person. That is, when we ask, e.g. “Kennst du” (do you know) the following word has to be a noun.

Here are some example sentences:

Kennst du das Buch von ….? – Do you know the book by ….? (Ja, ich kenne das Buch von ….)

Kennst du ihn? – Do you know him? (Ja, ich kenne ihn.)

Kennt er sie? – Does he know her. (Ja, er kennt sie)

Kennt Martin Sabine? – Does Martin know Sabine? (Ja, Martin kennt Sabine.)

In this type of sentence you cannot use the verb “wissen”. You can neither ask “Weißt du das Buch/ihn/sie?” nor can you answer “Ja, ich weiß das Buch/ihn/sie.”

Additionally, I want to mention that it is sometimes also possible to substitute “kennen” with “wissen”, e.g. instead of “Kennst du meinen Namen” you can also ask “Weißt du meinen Namen” (Do you know my name?). Nevertheless, my explanation represents a very reliable basic rule. So whenever you are pondering if you can opt for “wissen” when asking about a thing or person you will always be safe with “kennen”.