Learn Hardcore German: Zu viel Kaffee ist auf Dauer nicht gut für den Körper. - Too much coffee is not good for the body in the long run.

So in the sentence “Zu viel Kaffee ist auf Dauer nicht gut…”, it must be two words, because it’s just the normal “too much”, not the noun “an excess”.

Why is there no article before “Kaffee”? Why not “Zu viel der Kaffee” or “Zu viel des Kaffees”?

In German, with mass nouns and uncountable substances (like coffee, water, sugar), you often leave out the article when you talk about them in general or in an indefinite amount:

Ich trinke gern Kaffee. = I like drinking coffee.
Sie trinkt viel Wasser. = She drinks a lot of water.

Here, “Zu viel Kaffee” means “too much coffee (in general)”, so no article is needed.

If you add an article, it changes the meaning:

Zu viel des Kaffees = too much of the coffee (a specific coffee that was mentioned before)

That would be grammatically correct but much more specific and would sound odd in this general health statement.

Why is the verb “ist” (singular) and not “sind” (plural)? Doesn’t “zu viel Kaffee” mean “too many coffees”?

Grammatically, the subject is “Zu viel Kaffee”, and the main noun is “Kaffee” (a mass noun, singular), not “cups of coffee”.

So German treats it as singular:

Zu viel Kaffee ist nicht gut. ✔
(Too much coffee is not good.)

It’s similar to English: we also say “Too much coffee is bad for you”, not “are bad for you”.

If you explicitly counted individual coffees, you’d use a plural subject:

Zu viele Kaffees sind nicht gut. = Too many coffees are not good.
(Here Kaffees would mean separate servings/types, and this is rarer.)

What exactly does “auf Dauer” mean? Is it literally “on duration”?

Literally, “auf Dauer” could be broken down as “on duration”, but it’s used idiomatically.

In normal English it means:

in the long run
over time
in the long term

So:

Zu viel Kaffee ist auf Dauer nicht gut für den Körper.
≈ Too much coffee isn’t good for your body in the long run.

“auf Dauer” focuses on the idea that the negative effect appears if you do it for a long time, not necessarily from a single occasion.

Where can “auf Dauer” go in the sentence? Can I move it to the end?

The most natural positions are:

Zu viel Kaffee ist auf Dauer nicht gut für den Körper. ✔
Zu viel Kaffee ist nicht gut für den Körper auf Dauer. (possible, but sounds less smooth and more spoken)

“auf Dauer” is an adverbial phrase (like “in the long run”), and German word order is fairly flexible. However, the version in your sentence is the most idiomatic and neutral.

If you put “auf Dauer” right at the end, it can sound a bit tagged-on or stylistically weaker.

Why is it “für den Körper” and not “für der Körper”?

The preposition “für” in German always takes the accusative case.

der Körper (nominative – subject)
den Körper (accusative – direct object / after certain prepositions)

Because “für” requires accusative, you must say:

für den Körper ✔
not
für der Körper ✘

This is a fixed rule: für + Akkusativ always.

How do I know that “Körper” is masculine, so that it becomes “den Körper”?

You usually have to learn the gender together with the noun:

der Körper = the body (masculine)
die Hand = the hand (feminine)
das Bein = the leg (neuter)

A good habit is to always learn nouns with their article:

not just Körper, but der Körper

Then the cases follow from that:

Nominative: der Körper
Accusative: den Körper
Dative: dem Körper
Genitive: des Körpers

In your sentence, “für den Körper” uses the accusative.

Why is “Körper” capitalized? I thought only names are capitalized in English.

In German, all nouns are capitalized, not just names.

So:

der Körper (body)
der Kaffee (coffee)
die Dauer (duration)

It’s a key feature of German spelling. As soon as a word is a noun, it gets a capital letter at the beginning, even in the middle of a sentence.

What’s the difference between “Körper” and “Gesundheit” here? Could I say “…nicht gut für die Gesundheit”?

Yes, you could say:

Zu viel Kaffee ist auf Dauer nicht gut für die Gesundheit. ✔
= Too much coffee isn’t good for your health in the long run.

Nuance:

der Körper = the body, the physical organism
die Gesundheit = health, the state of being healthy

In many health-related sentences, you can use either:

nicht gut für den Körper = not good for your body (emphasis on the physical body)
nicht gut für die Gesundheit = not good for your health (slightly more abstract)

Both are natural; the original just chooses to highlight the body.

Why is it “nicht gut” and not “schlecht”? Aren’t both “not good”?

Both “nicht gut” and “schlecht” can be translated as “not good”, but they have slightly different tones:

nicht gut = not good, not healthy, may imply “problematic”, “unhealthy”
schlecht = bad, more strongly negative

In health contexts, German often likes the softer “nicht gut”:

Das ist nicht gut für deine Gesundheit.
(That’s not good for your health.)

Saying:

Zu viel Kaffee ist auf Dauer schlecht für den Körper.

is also grammatically correct and understandable, but sounds stronger, more judgmental. The original phrasing is a bit more moderate.

Why do we use “für” before “den Körper”? Could we use another preposition?

German normally uses the pattern:

gut / schlecht + für + Akkusativ

to express “good/bad for (something/someone)”:

Das ist gut für dich. = That’s good for you.
Rauchen ist schlecht für die Lunge. = Smoking is bad for the lungs.

So for “good/bad for the body”, “für den Körper” is the standard and idiomatic choice.

Other prepositions would change the meaning:

zu dem Körper = to the body
auf den Körper = onto the body

They don’t fit here.

Could I leave out “auf Dauer” and just say “Zu viel Kaffee ist nicht gut für den Körper”?

Yes, that is absolutely grammatical and natural:

Zu viel Kaffee ist nicht gut für den Körper. ✔

The difference in meaning:

Without “auf Dauer”:
A general statement that too much coffee is not good for the body (could be understood as “in general”).
With “auf Dauer”:
Emphasizes that the harm appears over time / in the long run, not necessarily from one-time consumption.

So “auf Dauer” adds a time-related nuance.

Is “auf Dauer” a fixed expression, or is it a regular combination of “auf” + “Dauer”?

Both. Grammatically, it’s “auf” (on) + “Dauer” (duration), but in everyday language, “auf Dauer” behaves like a fixed idiomatic phrase meaning:

in the long run
permanently / over a long period

You will commonly see it as a chunk:

Das ist auf Dauer anstrengend. = That’s exhausting in the long run.
Man kann das nicht auf Dauer so machen. = You can’t do it like that forever / in the long term.

So it’s useful to remember “auf Dauer” as one unit with the meaning “in the long run”.

Could I say “Sehr viel Kaffee” instead of “Zu viel Kaffee”? What’s the difference?

There’s an important difference:

sehr viel Kaffee = a lot of coffee, very much coffee
(just describes a large quantity, no judgment)
zu viel Kaffee = too much coffee
(says the amount is excessive / more than is good)

Your sentence is making a negative evaluation of the amount, so “zu viel” is the correct choice:

Zu viel Kaffee ist auf Dauer nicht gut für den Körper. ✔

If you said:

Sehr viel Kaffee ist auf Dauer nicht gut für den Körper.

it would still be understandable, but stylistically, “zu viel” fits better, because the sentence is exactly about the amount being unhealthy, not just big.