sein — to be

1.sein — to be

sein means to be and is one of the most important verbs in German.

It is also highly irregular. Its present-tense forms do not follow the normal pattern of regular verbs such as lernen or machen.

The six forms needed at beginner level:

ich bin
du bist
er / sie / es ist
wir sind
ihr seid
sie / Sie sind

Core idea: choose the form of sein from the subject. Then add the information that describes, identifies or locates that subject.

2.sein is the German verb “to be”

The infinitive is:

sein

Examples:

In all four sentences, sein connects the subject with new information.

Ich     → bin  → Anna
Du      → bist → müde
Berlin  → ist  → groß
Wir     → sind → zu Hause

So sein often works like a link:

SUBJECT + form of sein + information about the subject

3.The present-tense forms of sein

The complete A1 paradigm:

The most important forms to memorize:

bin — bist — ist — sind — seid — sind

These forms appear constantly in everyday German.

4.Why sein is irregular

With a regular verb such as lernen, the stem is easy to see:

lernen → lern-
ich lerne
du lernst
er lernt

With sein, the present forms look very different:

sein
bin
bist
ist
sind
seid

They cannot be built reliably by taking a simple stem and adding the normal endings.

That is why it is better to learn:

ich bin
du bist
er / sie / es ist
wir sind
ihr seid
sie / Sie sind

as one complete pattern.

Forms such as ich seine or du seinst are not standard German. The language uses bin, bist, ist, sind and seid.

5.Match the verb form to the subject

The subject tells which form of sein to use.

ich → bin
du → bist
er / sie / es → ist
wir → sind
ihr → seid
sie / Sie → sind

Compare:

The information müde stays the same. Only the verb changes because the subject changes.

6.Nouns can be subjects too

The subject is not always a personal pronoun.

A name or noun can also determine the form of sein.

Singular subjects normally use ist:

Plural subjects use sind:

A useful beginner shortcut:

one person / thing → often ist
more than one      → often sind

This shortcut does not replace the full pronoun table, but it helps when the subject is a noun.

7.Pattern 1: sein + identity

One very common use of sein is to say who or what someone or something is.

subject + sein + identity

Examples:

Here, the part after sein identifies the subject.

Ich → Maria
Er  → Student
Sie → Ärztin
Das → ein Problem

8.Professions after sein

When German simply states a profession, the profession often appears without an article.

Compare this with identifying a specific person:

Das ist der Lehrer.

The first sentence says what someone does or is by profession. The second points to a particular teacher.

At A1, the useful pattern is:

Ich bin + profession
Er / Sie ist + profession

9.Pattern 2: sein + adjective

sein is very often followed by an adjective that describes the subject.

subject + sein + adjective

Examples:

A useful point for beginners:

After sein, the adjective in these sentences does not take an adjective ending.

Der Kaffee ist heiß.
Die Suppe ist heiß.
Die Getränke sind heiß.

The form heiß stays unchanged.

10.Temporary state or general property

The same basic pattern can express different kinds of information.

A temporary state:

A more general description:

At A1, no special grammar structure is needed for this difference. The sentence pattern is the same:

subject + sein + adjective

11.Pattern 3: sein + place

sein can also tell where someone or something is.

subject + sein + place

Examples:

The form of sein still depends on the subject:

ich  → bin
Paul → ist
wir  → sind

The place expression comes after it.

12.Three core A1 uses side by side

The same verb can connect the subject with different kinds of information.

A useful mental model:

                 identity
subject + sein + description
                 location

The form of sein changes. The type of information after it can change too.

13.das ist is an extremely common pattern

At beginner level, this pattern appears constantly:

Das ist ...

Examples:

das can point to a person, thing or situation. The verb form is ist.

For more than one thing:

Das sind meine Freunde.

This is a very common fixed-looking pattern worth recognizing early.

14.es ist is also common

Another frequent combination:

Es ist ...

Examples:

Here, es is the subject and therefore the verb is ist.

Further impersonal uses of es appear later. For now, Es ist ... is a very common sentence pattern to recognize.

15.Statements with sein

In a simple statement, the conjugated verb normally belongs in the central verb position of the sentence.

Examples:

The important point on this page is the form itself:

Ich → bin
Anna → ist
Wir → sind

The separate word-order pages explain the full position rules in more detail.

16.Yes/no questions with sein

A yes/no question normally starts with the conjugated verb.

With sein:

Bist du müde?
Ist Anna hier?
Seid ihr fertig?
Sind Sie Herr Klein?

The same forms appear as in statements. Only the sentence structure changes.

Du bist müde. → Bist du müde?

17.W-questions with sein

sein also appears in very common W-questions.

The W-word asks for the missing information, while the form of sein still matches the subject.

Wo + bist + du?
Wo + sind + die Kinder?

18.Negative sentences with sein

With an adjective or place expression, nicht is very common:

With a noun, kein may also appear:

Er ist kein Arzt.

This page does not teach the full negation system. The important point is that the form of sein itself does not change because of negation.

ich bin
ich bin nicht

er ist
er ist nicht

19.Sie sind can mean two different things

The form sind is used with both lowercase sie and formal Sie.

sie sind = they are
Sie sind = you are (formal)

Example:

Sie sind müde.

This written sentence can have two meanings depending on context:

• They are tired.
• You are tired. — formal address

Capitalization helps in writing, and context helps in speech.

20.ihr seid is a form worth learning as one chunk

The ihr form is:

ihr seid

Examples:

A frequent beginner error is to use sind with ihr. Standard German requires:

ihr seid

21.The most useful memory groups

Instead of seven unrelated lines, the paradigm can be organized into small groups.

Singular

ich bin
du bist
er / sie / es ist

Plural and formal Sie

wir sind
ihr seid
sie / Sie sind

Notice that sind appears three times:

wir sind
sie sind
Sie sind

This makes the second half of the paradigm easier to remember.

22.Connection to the sentence core

The sentence-core model is:

subject + conjugated verb

With sein, this becomes:

Ich + bin
Du + bist
Anna + ist
Wir + sind

Then the information that completes the idea is added:

So sein is an excellent verb for seeing subject–verb agreement clearly.

The stable form map:

ich        bin
du         bist
er/sie/es  ist
wir        sind
ihr        seid
sie/Sie    sind

Connected with the most common beginner patterns:

sein + identity
sein + adjective
sein + place

23.Typical mistakes

Using the infinitive after a subject

Incorrect: Ich sein müde.. Correct: Ich bin müde..

A normal simple sentence needs the personal form bin, not the infinitive sein.

Building sein like a regular verb

sein is irregular. Its forms are learned directly.

Using ist with every subject

The verb must match the subject.

Confusing seid and sind

Incorrect: Ihr sind fertig.. Correct: Ihr seid fertig..

Compare with sind: Wir sind fertig., Sie sind fertig..

Adding an adjective ending after sein

Incorrect (when the meaning is only “the coffee is hot”): Der Kaffee ist heißer.. Correct: Der Kaffee ist heiß..

After sein, a simple descriptive adjective normally stays in its basic form.

heißer has another meaning: “hotter”.