Zieh die Bremse fest.

Zieh is the informal singular imperative form of the verb, used when giving a command to one person you address as du.

The full verb is festziehen. Its du form is:

• du ziehst die Bremse fest

To make the command, German usually drops du and uses the imperative form:

• Zieh die Bremse fest.

So zieh here means pull! / tighten! as a command.

In German, commands usually leave out the subject.

So instead of saying:

• Du ziehst die Bremse fest. = you are tightening the brake

you say:

• Zieh die Bremse fest. = tighten the brake / pull the brake tight

You can add du for emphasis:

• Zieh du die Bremse fest.

But normally, just Zieh ... is the standard way to give the command.

Because the verb is actually festziehen, which is a separable verb.

Its two parts are:

• ziehen = to pull
• fest- = tight / firmly

In many sentence types, separable prefixes move to the end:

• Ich ziehe die Bremse fest.
• Du ziehst die Bremse fest.
• Zieh die Bremse fest.

But in the infinitive, they stay together:

• festziehen

So the sentence is based on the verb festziehen, not just ziehen by itself.

Literally, festziehen means something like to pull tight or to tighten.

With die Bremse, it means to tighten/apply the brake firmly.

So although ziehen on its own often means to pull, in this sentence the full idea comes from festziehen.

This is a good example of why separable verbs should be learned as a whole unit.

Bremse is a feminine noun, so its basic article is die:

• die Bremse = the brake

In this sentence, die Bremse is the direct object of the verb, so it is in the accusative case.

For feminine singular nouns, the accusative article is also die, so it looks the same as the nominative:

• nominative: die Bremse
• accusative: die Bremse

That is why you see die here.

Not especially irregular, but it may look a little unusual at first.

The verb is ziehen. Its forms include:

• ich ziehe
• du ziehst
• er/sie/es zieht

The du-imperative is usually formed from the verb stem without -st, so:

• ziehen → zieh!

That is why it is zieh, not ziehst.

Yes. Zieh die Bremse fest. is the command form for one person you address as du.

Other versions would be:

• Zieht die Bremse fest. = command to several people (ihr)
• Ziehen Sie die Bremse fest. = formal command (Sie)

So if you are speaking to one friend, child, or someone you would normally call du, Zieh die Bremse fest. is appropriate.

Possibly, depending on context, but it is not exactly the same structure.

• die Bremse anziehen = to apply / pull on the brake
• die Bremse festziehen = to tighten the brake firmly

Both are real German expressions, but festziehen emphasizes making it tight/firm.

So a learner should understand that festziehen is a specific separable verb with its own meaning, not just a random combination of ziehen + fest.

Zieh is pronounced with a long ie sound, roughly like tsee plus a gentle final h that mainly marks the vowel as long.

Very roughly for English speakers:

• zieh ≈ tsee-uh said quickly, but really as one syllable

The z in German is pronounced like ts, so:

• zieh begins with a ts sound, not an English z sound.

The final h is not strongly pronounced by itself; it mainly shows that the vowel is long.

Not always.

In many cases, fest does mean something like:

• tight
• firm
• securely

But in separable verbs such as festziehen, the meaning is often more natural in English as a single verb:

• tighten
• fasten firmly
• secure

So while understanding fest literally is helpful, it is better to learn festziehen as one complete verb with its own meaning.