Der Gegenverkehr ist heute stark, trotzdem bleibt meine Schwester ruhig.

Gegenverkehr means oncoming traffic—traffic coming toward you from the opposite direction.

It is made up of:

• gegen = against / opposite
• Verkehr = traffic

So der Gegenverkehr is a very common road-traffic word in German.

Because Gegenverkehr is the subject of the first clause:

• Der Gegenverkehr ist heute stark.

The subject takes the nominative case, and der is the nominative masculine article.

A quick breakdown:

• der Gegenverkehr = the subject
• ist = is
• heute stark = strong/heavy today

If it were an object, you might see den Gegenverkehr or dem Gegenverkehr, but not here.

Yes, stark literally means strong, but with traffic it often means heavy.

So:

• Der Gegenverkehr ist stark = The oncoming traffic is heavy

This is similar to how German often uses stark in situations where English prefers heavy:

• starker Regen = heavy rain
• starker Verkehr = heavy traffic

So this is normal, idiomatic German.

Because the sentence contains two main clauses:

1. Der Gegenverkehr ist heute stark
2. trotzdem bleibt meine Schwester ruhig

In German, two independent main clauses are often separated by a comma.

Also, trotzdem here is not a subordinating conjunction like weil or obwohl. It is an adverb meaning nevertheless / even so / still.

So the comma helps separate the two complete thoughts.

Because trotzdem is an adverb placed in position 1, and in a German main clause, the finite verb must come second.

So the pattern is:

• trotzdem = position 1
• bleibt = position 2
• meine Schwester = after the verb

That gives:

• Trotzdem bleibt meine Schwester ruhig.

This is a very important German word-order rule: when something other than the subject comes first, the verb still stays in second position.

Compare:

• Meine Schwester bleibt ruhig.
• Heute bleibt meine Schwester ruhig.
• Trotzdem bleibt meine Schwester ruhig.

In all of these, the conjugated verb bleibt is in second position.

Not exactly.

• trotzdem = nevertheless / even so / still
• obwohl = although

The big grammar difference is:

trotzdem

Introduces a main clause, so the verb stays in second position:

• Der Gegenverkehr ist heute stark, trotzdem bleibt meine Schwester ruhig.

obwohl

Introduces a subordinate clause, so the verb goes to the end:

• Obwohl der Gegenverkehr heute stark ist, bleibt meine Schwester ruhig.

Both can express contrast, but they are not interchangeable in grammar.

Because bleiben means to remain / to stay.

So:

• ist ruhig = is calm
• bleibt ruhig = remains calm / stays calm

In this sentence, the idea is that despite the heavy oncoming traffic, she continues to be calm. That is why bleibt is a better choice than ist.

Because ruhig is being used as a predicative adjective, not an adjective directly before a noun.

After verbs like:

• sein = to be
• werden = to become
• bleiben = to remain

the adjective normally does not take an ending.

So:

• Meine Schwester bleibt ruhig.
• Meine Schwester ist ruhig.
• Meine Schwester wird ruhig.

But if the adjective comes before a noun, then it does take an ending:

• meine ruhige Schwester = my calm sister

Because meine Schwester is the subject of the second clause, so it must be in the nominative case.

• meine Schwester = nominative
• meiner Schwester = usually dative or genitive, depending on the context

Here the structure is:

• trotzdem bleibt meine Schwester ruhig

So meine Schwester is the person doing the action of bleibt.

Sometimes in natural English, yes—but not as a direct grammar match.

In this sentence, English might say:

• The oncoming traffic is heavy today, but my sister remains calm.
• The oncoming traffic is heavy today; nevertheless, my sister remains calm.

German trotzdem is closer in meaning to:

• nevertheless
• even so
• all the same
• still

German aber is the more direct equivalent of but:

• Der Gegenverkehr ist heute stark, aber meine Schwester bleibt ruhig.

That said, trotzdem often sounds a bit stronger or more formal than aber.

Yes. German is flexible, but the word order changes according to emphasis.

The original sentence is:

• Der Gegenverkehr ist heute stark.

You could also say:

• Heute ist der Gegenverkehr stark.

Both are correct. The difference is mostly emphasis:

• Der Gegenverkehr ist heute stark → focus starts with the oncoming traffic
• Heute ist der Gegenverkehr stark → focus starts with today

In either case, the conjugated verb still stays in second position in a main clause.

Yes. It sounds natural and grammatically correct.

A native speaker would understand it immediately. The vocabulary is standard, and the structure is a good example of:

• a main clause
• a contrast with trotzdem
• correct verb-second word order
• bleiben + adjective

So it is a useful model sentence for learners.