این قهوه بد است.

A common, careful pronunciation is:

• این = in (like in in English, but shorter)
• قهوه = qah-ve (often close to gah-ve for many learners; the first sound ق is a “back” k/g sound in many accents)
• بد = bad (similar to English bad, but with a shorter vowel)
• است = ast (often reduced in speech)

Putting it together: in qahve bad ast (or in casual speech, closer to in qahve bad-e).

قهوه means coffee. Persian normally doesn’t write short vowels, so you don’t see the a and e vowels explicitly. The final ـه here is part of the spelling and the word is pronounced with a final -e sound: qahve.

In Persian, a very common pattern is: [subject] + [adjective/complement] + [copula] So you get:

• این قهوه (this coffee) + بد (bad) + است (is)

This is normal Persian sentence structure.

Yes, very often in everyday Persian the present-tense is/are is omitted when it’s obvious:

• این قهوه بد است. (more formal / written / careful)
• این قهوه بده. or این قهوه بدِه. (common casual speech/writing)
• این قهوه بد (possible in very informal contexts, but less “complete”)

Both can translate as is, but they’re used differently:

• است is the standard copula in formal speech and writing (and also used in careful spoken Persian).
• هست is very common in conversation and can feel more “existential” or simply more colloquial.

For this sentence, این قهوه بد است is perfectly standard; a conversational alternative is این قهوه بدِه or این قهوه بد هست (less common than بدِه, but still possible).

Persian doesn’t have an exact equivalent of English a/the. Definiteness is often shown by context or by words like این (this) / آن (that). Here, این already makes it definite: this coffee.

If you wanted a coffee is bad (more like “some coffee is bad”), Persian would express that differently and usually with context, or with یه (one/a) in speech.

By default, این قهوه points to a specific coffee that’s contextually “near” (physically or in the conversation).
If you mean this kind/type of coffee, Persian often adds a word like:

• این نوع قهوه = this type of coffee

Context can also make این قهوه mean “this (particular) coffee we’re talking about.”

You typically put نیست (is not) at the end:

• این قهوه بد نیست. = This coffee is not bad.

In more formal style you might see بد نیست much more than something like بد نمی‌باشد (which is quite formal/administrative).

You can use rising intonation:

• این قهوه بد است؟

Or add آیا at the start (more formal/written):

• آیا این قهوه بد است؟

In everyday speech you might hear:

• این قهوه بده؟

بد is straightforwardly bad, but the strength depends on tone and context.
If you want a softer criticism like “not good,” Persian often prefers a negated positive:

• این قهوه خوب نیست. = This coffee isn’t good.

That can sound less harsh than بد است.

Yes. The typical order is:

• قهوهٔ بد = bad coffee (noun + adjective)

But in your sentence, بد is not directly modifying the noun as a noun phrase; it’s the predicate adjective after the subject:

• این قهوه (subject) + بد (predicate) + است (copula)

Both patterns are common, just different structures.

Ezāfe is used to link nouns to adjectives/possessors inside a noun phrase, like:

• قهوهٔ بد = bad coffee
• قهوهٔ من = my coffee

In این قهوه بد است, بد isn’t inside the noun phrase این قهوه; it’s the predicate of the sentence, so you don’t use ezāfe there.

A very natural everyday version is:

• این قهوه بده. (common casual)

You might also hear emphasis with intonation:

• این قهوه خیلی بده. = This coffee is really bad.