Sein
'Sein' (to be) is one of the most important and irregular verbs in German. It's used constantly in everyday communication.
It's completely irregular and must be memorized. It's also used as an auxiliary verb in perfect tense for certain verbs.
This lesson covers all forms and uses of 'sein' in German.
Explanation
Present tense conjugation: ich bin, du bist, er/sie/es ist, wir sind, ihr seid, sie/Sie sind.
Simple past: ich war, du warst, er/sie/es war, wir waren, ihr wart, sie waren.
Past participle: gewesen. Perfect: 'Ich bin gewesen' (I have been).
'Sein' is used as an auxiliary verb in perfect tense for verbs of movement and state change: 'Ich bin gegangen' (I have gone).
'Sein' is used to express identity, location, time, and characteristics: 'Ich bin Student' (I am a student), 'Er ist in Berlin' (He is in Berlin).
Sein - All Tenses
| Tense | ich | du | er/sie/es | wir | ihr | sie |
|---|---|---|---|---|---|---|
| Present | bin | bist | ist | sind | seid | sind |
| Simple Past | war | warst | war | waren | wart | waren |
| Perfect | bin gewesen | bist gewesen | ist gewesen | sind gewesen | seid gewesen | sind gewesen |
Examples
Ich bin Student.
I am a student.
Er ist in Berlin.
He is in Berlin.
Wir sind müde.
We are tired.
Sie war gestern hier.
She was here yesterday.
Ich bin nach Hause gegangen.
I have gone home.
Common Mistakes
Ich bist
Ich bin
'Ich' requires 'bin', not 'bist'. 'Bist' is for 'du'.
Er sind
Er ist
'Er' requires 'ist', not 'sind'. 'Sind' is for 'wir/sie'.
Related Exercises
Multiple Choice
Test this grammar topic with multiple-choice questions and instant feedback.
Start exercise →Write the Form
Active recall: type the correct article, ending, or form yourself.
Start exercise →Complete the Sentence
Fill gaps in real sentences to practice the rule in context.
Start exercise →Common Mistakes
Spot the only correct sentence and avoid frequent grammar traps.
Start exercise →Related Topics
Frequently Asked Questions
How do I know which article to use?
German articles (der, die, das) depend on the gender of the noun. While there are some patterns, many nouns must be memorized. Practice and exposure to German will help you learn them naturally.
What's the difference between definite and indefinite articles?
Definite articles (der, die, das) mean 'the' and refer to specific things. Indefinite articles (ein, eine) mean 'a/an' and refer to non-specific things. Both must match the noun's gender: use 'ein' for masculine/neuter and 'eine' for feminine.
Are there rules for determining noun gender?
While there are some helpful patterns (e.g., words ending in -ung are usually feminine), there are many exceptions. The best approach is to learn nouns with their articles from the beginning.
What happens if I use the wrong article?
While using the wrong article is a common mistake, native speakers will usually still understand you. However, using the correct article is important for sounding natural and fluent in German.