Learn Hardcore German: Alle Einladungen müssen heute noch verschickt werden. - All invitations have to be sent out today.

Einladungen is the plural of die Einladung (invitation).
The sentence is talking about all the invitations, not just one, so plural is required.

Singular: die Einladung – the invitation
Plural: die Einladungen – the invitations

Because the subject is plural, the verb also has to be plural (müssen, not muss).

What gender is Einladung, and how is its plural formed?

Einladung is a feminine noun: die Einladung.

The plural is made in a very typical feminine way:

Add -en to form the plural
The article die stays the same in nominative singular and plural

So:

Singular: die Einladung
Plural: die Einladungen

In this sentence, Alle Einladungen is nominative plural, because it’s the subject.

Why is there no article like die before Einladungen? Why not Alle die Einladungen?

In German you normally use either a determiner like alle, viele, meine, diese or a definite article like die — not both together.

So you say:

Alle Einladungen – all invitations
Die Einladungen – the invitations
Meine Einladungen – my invitations

But not:

✗ Alle die Einladungen (incorrect in this meaning)

Alle is already doing the job of the article here, so you don’t add die.

Why is Alle capitalized? Is alle always written with a capital letter?

Here Alle is capitalized only because it is the first word of the sentence.

In general:

As a determiner/pronoun, alle is written with a lowercase a:
- alle Einladungen, alle Leute, wir alle
At the beginning of a sentence, it is capitalized like any first word:
- Alle Einladungen müssen …

So the rule is not specific to alle, but to all sentence-initial words.

Why is it müssen and not muss?

The verb müssen has to agree with its subject:

Subject: Alle Einladungen → plural
So the verb must be 3rd person plural: sie müssen

Conjugation of müssen in the present tense:

ich muss
du musst
er/sie/es muss
wir müssen
ihr müsst
sie/Sie müssen

Since Alle Einladungen = sie (they), you need müssen.

What kind of structure is müssen … verschickt werden? Why are there so many verbs?

This is a combination of:

A modal verb: müssen (must, have to)
The passive voice formed with werden
A past participle: verschickt

Together they express: “must be sent (by someone)”.

müssen – expresses obligation
werden – auxiliary verb for the process passive (Vorgangspassiv)
verschickt – past participle of verschicken (to send [out])

So structurally it’s:

müssen + Partizip II + werden
must + sent + be → must be sent

Why is verschickt before werden at the end? Could it also be werden verschickt?

In this sentence, the finite (conjugated) verb is the modal müssen, so it takes the second position in the main clause, and all the other verb forms go to the end:

Alle Einladungen – first idea (subject)
müssen – conjugated verb in position 2
heute noch verschickt werden – rest of the verb cluster at the end

In a verb cluster with a modal verb and werden-passive, the usual word order is:

[Participle] + [Infinitive]
verschickt werden

You say:

… müssen verschickt werden.

But if you remove the modal verb and keep just the passive in a main clause, then werden is conjugated and goes to position 2, and the participle comes last:

Alle Einladungen werden heute noch verschickt.
(no modal verb; simple present passive)

Why is werden in the infinitive and not wird or werden (conjugated)?

Only one verb in the clause is conjugated: the modal verb müssen.

Whenever a modal verb is used with another verb (or a passive structure), the other verbs stay in the infinitive or participle form and go to the end:

Ich muss gehen. – I must go.
Die Einladungen müssen verschickt werden. – The invitations must be sent.

So:

müssen → conjugated (müssen, because the subject is plural)
verschickt → past participle
werden → infinitive

What exactly does noch mean here, and what nuance does it add?

In heute noch, the word noch adds the idea of “still within today / by the end of today / not later than today.”

Without noch:

Alle Einladungen müssen heute verschickt werden.
→ They have to be sent today (plain statement of time).

With heute noch:

Alle Einladungen müssen heute noch verschickt werden.
→ They still need to be sent today (implied: they haven’t been sent yet, and today is the deadline).

It often carries a slight feeling of urgency or a last chance within today.

Is there a difference between heute noch and noch heute?

In most everyday contexts, heute noch and noch heute mean almost the same and can be used interchangeably:

Alle Einladungen müssen heute noch verschickt werden.
Alle Einladungen müssen noch heute verschickt werden.

Both mean: the invitations must still be sent today.

Subtle nuance (not always strong or important):

heute noch – a bit more neutral, very common in speech.
noch heute – can sound slightly more emphatic on “today (and not later)”, often used in written or formal language for emphasis.

For a learner, you can treat them as equivalent in meaning.

Why is passive used here instead of a normal active sentence?

The passive in Alle Einladungen müssen heute noch verschickt werden focuses on the invitations and the action, not on who sends them.

Passive:
- Alle Einladungen müssen heute noch verschickt werden.
  → Focus: the invitations, the fact that they must be sent.
Possible active version:
- Jemand muss heute noch alle Einladungen verschicken.
  → Someone has to send all the invitations today.

German uses the passive in the same kind of contexts as English: when the doer is unknown, unimportant, or obvious from the situation (e.g. coworkers in an office).

How do I convert this sentence into an active one?

Passive:

Alle Einladungen müssen heute noch verschickt werden.

A natural active version would be:

Jemand muss heute noch alle Einladungen verschicken.
(Someone has to send all the invitations today.)

Or, if you know the subject:

Wir müssen heute noch alle Einladungen verschicken.
Das Büro muss heute noch alle Einladungen verschicken.

Notice the changes:

Alle Einladungen moves from subject → object
A new subject (e.g. wir, jemand) appears
The passive verschickt werden becomes active verschicken

What is the difference between müssen and sollen here? Could I say Alle Einladungen sollen heute noch verschickt werden?

Yes, you can say Alle Einladungen sollen heute noch verschickt werden, but there is a nuance:

müssen – strong necessity/obligation, often felt directly by the speaker:
- They have to be sent today (because of a clear need or rule).
sollen – often implies that the obligation comes from someone else’s will, order, or plan:
- They are supposed to be sent today (because that’s what was decided/ordered).

In many contexts the difference is small, but:

müssen sounds more like a strict must
sollen can sound more like are to / are supposed to

Why verschickt and not geschickt? What is the difference between schicken and verschicken?

Both are related, but there’s a nuance:

schicken – to send (general), can be used in many contexts
verschicken – to send out, often suggests sending things (especially in larger numbers), e.g. letters, emails, parcels

In this context:

Alle Einladungen müssen heute noch verschickt werden.
→ suggests: sending out invitations (maybe to many people), which fits very well.

You could hear:

Alle Einladungen müssen heute noch geschickt werden.

This is understandable, but verschicken (or versenden) is stylistically more typical when talking about sending a batch of letters/emails/invitations.

Could I also say gesendet or versendet instead of verschickt?

Yes, you could use synonyms:

Alle Einladungen müssen heute noch gesendet werden.
Alle Einladungen müssen heute noch versendet werden.

Nuances (often quite small):

verschicken – very common for letters, parcels, emails, invitations; everyday style.
versenden – similar meaning, sometimes sounds a bit more formal/technical (e.g. in business, IT: Newsletter versenden).
senden → gesendet – also fine, but can sound slightly more formal or technical; also used in media (Sendungen) and technology (Daten senden).

In ordinary speech about invitations, verschicken is probably the most natural.

Is this sentence present tense or future? In English I’d probably say “have to be sent today” or “must still be sent today”.

Grammatically, it is in the present tense:

müssen – present
verschickt werden – passive construction in the present

However, just like in English, the German present can refer to future time if a time expression is present:

Alle Einladungen müssen heute noch verschickt werden.
= They must (still) be sent today (by the end of today).

So it’s present tense form, but with a future-like meaning because of heute noch. You normally don’t need werden for the future here.