Die Drosselung beginnt heute.

Because Drosselung is a feminine noun in German.

A very useful clue is the ending -ung: nouns ending in -ung are almost always feminine.

Examples:

• die Lösung
• die Meinung
• die Rechnung
• die Drosselung

So in the sentence, the correct article is die.

Drosselung is a noun. It comes from the verb drosseln, which means something like to reduce, to throttle, or to restrict, depending on context.

The ending -ung often turns a verb into a noun that describes:

• the process
• the action
• or sometimes the result

So:

• drosseln = to reduce/throttle
• die Drosselung = the reduction / throttling / restriction

This is a very common word-building pattern in German.

Because all nouns are capitalized in German, not just proper names.

So:

• die Drosselung
• der Tisch
• das Haus
• heute beginnt die Arbeit

This is one of the easiest visual clues for spotting nouns in German.

Because the subject is die Drosselung, which is third person singular: it begins.

The verb is beginnen = to begin. Its present-tense forms include:

• ich beginne
• du beginnst
• er/sie/es beginnt
• wir beginnen
• ihr beginnt
• sie/Sie beginnen

Since die Drosselung is singular, German uses beginnt.

It is in the nominative case, because it is the subject of the sentence.

You can ask:

• What begins today?
• Die Drosselung.

That tells you it is the subject, so it is nominative.

For feminine nouns, the nominative singular article is die.

Because German word order is flexible, and putting heute at the end is a very natural option.

The key rule is that in a normal main clause, the conjugated verb must be in position 2:

• Die Drosselung beginnt heute.

Here:

1. Die Drosselung
2. beginnt
3. heute

You could also say:

• Heute beginnt die Drosselung.

That is also correct. It puts more emphasis on today.

So the sentence you have is simply a neutral, standard word order.

Yes. In this sentence, beginnen is used intransitively, meaning it does not need a direct object.

• Die Drosselung beginnt heute. = The throttling/reduction begins today.

German beginnen can also be used with an object:

• Sie beginnt die Arbeit. = She begins the work.

So both patterns are possible:

• something begins
• someone begins something

Yes. Heute is a time adverb meaning today.

It tells you when the action happens:

• Die Drosselung beginnt heute.

Other common time adverbs work similarly:

• morgen = tomorrow
• gestern = yesterday
• jetzt = now
• bald = soon

Yes. The exact English word for Drosselung depends heavily on context.

Possible translations include:

• reduction
• throttling
• restriction
• limitation
• cutback

For example:

• in a technical context, throttling
• in energy or supply contexts, reduction or restriction
• in internet or data contexts, throttling

So the grammar stays the same, but the most natural English wording depends on what is being reduced or limited.

A rough English-friendly guide is:

DROSS-eh-loong

More precisely:

• Dross rhymes roughly with English cross (depending on accent)
• -elung is pronounced with the ng sound at the end, not a hard g

The stress is on the first syllable:

• DROS-se-lung

And beginnt is roughly:

• beh-GINT

So the full sentence sounds approximately like:

• dee DROSS-eh-loong beh-GINT hoy-tuh

Yes, in many contexts that would be possible.

• Die Drosselung beginnt heute.
• Die Drosselung fängt heute an.

Both mean that it starts today.

The difference is mainly style:

• beginnt sounds a bit more formal or neutral
• fängt ... an is often a little more conversational

In formal writing, beginnt is often the more natural choice.