Klick bitte nicht die falsche Schaltfläche an, sonst verschwindet das Formular.

Because the verb is anklicken, which is a separable verb.

• Full infinitive: anklicken = to click on
• In a main clause or command, the prefix an- separates and goes to the end:
  • Klick ... an
  • Ich klicke die Schaltfläche an

So Klick bitte nicht die falsche Schaltfläche an uses the normal separable-verb pattern.

Klick is an imperative, so it is giving a command: Click ...

It is the command form for du (informal singular you).

From du klickst, the imperative is:

• Klick!
• or slightly more formal/full: Klicke!

Both exist, but the shorter form Klick! is very common in everyday German.

Related forms:

• Klick! = command to one person informally
• Klickt! = command to several people informally
• Klicken Sie! = formal/polite command

Bitte softens the command, like please in English.

Yes, it can move around somewhat. German allows fairly flexible placement for bitte. For example:

• Klick bitte nicht die falsche Schaltfläche an.
• Bitte klick nicht die falsche Schaltfläche an.
• Klick nicht die falsche Schaltfläche an, bitte.

The version in your sentence sounds very natural and neutral.

In German, nicht usually comes before the part of the sentence it is negating.

Here, nicht die falsche Schaltfläche means not the wrong button. In context, that gives the natural meaning don’t click the wrong button.

This placement is normal and idiomatic. If you move nicht, the emphasis can change, and the sentence may sound less neutral.

So:

• Klick bitte nicht die falsche Schaltfläche an = natural warning
• the negation is focused on the object being clicked

It is the direct object of anklicken, so it is in the accusative case.

• Verb: anklicken
• Object: die falsche Schaltfläche

Schaltfläche is a feminine noun, and in the singular the definite article is:

• nominative: die
• accusative: die

So the article does not change visibly here. The phrase looks the same in nominative and accusative.

Also:

• falsche has the weak adjective ending -e because it comes after the definite article die

Usually, yes. In computer/interface language, Schaltfläche is the standard German word for an on-screen button.

A few related words:

• Schaltfläche = on-screen button/interface button
• Button = also used in German, especially in tech contexts
• Taste = key on a keyboard
• Schalter = switch, toggle, or physical control

So in this sentence, Schaltfläche is a very appropriate word for a UI button.

Sonst means otherwise or or else.

It introduces the consequence if the command is not followed:

• Klick bitte nicht die falsche Schaltfläche an, sonst verschwindet das Formular.
• Don’t click the wrong button, otherwise the form will disappear.

So sonst is linking the warning to its result.

Because sonst verschwindet das Formular is a main clause, and main clauses in German usually follow the verb-second rule.

Here:

• sonst takes the first position
• verschwindet is the finite verb, so it must come second
• das Formular comes after that

So the order is:

• sonst
  • verschwindet
    • das Formular

Sonst das Formular verschwindet would use subordinate-clause word order, which is not correct here.

The comma separates two clauses:

1. Klick bitte nicht die falsche Schaltfläche an
2. sonst verschwindet das Formular

This is very common in German when one clause is followed by a consequence clause, especially with words like sonst.

So the comma helps show the structure clearly:

• first the instruction
• then the consequence

In the second clause, das Formular is the subject.

• verschwindet = disappears
• The thing that disappears is das Formular

So this is not an object. The form itself is doing the action grammatically.

Also, Formular is a neuter noun, so its article is das.

That gives:

• das Formular verschwindet = the form disappears

It is informal, because of Klick, which is the command form for du.

If you wanted a formal version, you would say:

• Klicken Sie bitte nicht die falsche Schaltfläche an, sonst verschwindet das Formular.

So:

• Klick ... = informal, one person
• Klicken Sie ... = formal/polite

This is a very common distinction in German.