Το επιτόκιο είναι χαμηλό.

A good English-friendly approximation is:

to eh-pee-TOH-kee-oh EE-ne ha-mee-LOH

Stress falls on:

• -τό- in επιτόκιο
• εί- in είναι
• -λό in χαμηλό

A couple of sound notes:

• ει in είναι sounds like ee
• χ in χαμηλό is not exactly English h; it is a rougher sound, like the ch in German Bach or Scottish loch
• Greek accent marks show you which syllable is stressed

Το is the definite article, meaning the.

In this sentence, το goes with επιτόκιο:

• το επιτόκιο = the interest rate

Greek articles change for gender, number, and case, so το tells you that επιτόκιο is neuter singular here.

Επιτόκιο is neuter.

You can tell from:

• the article: το
• the adjective form: χαμηλό
• the noun ending: -ιο, which is very often neuter in Greek

So the pattern is:

• το επιτόκιο
• το χαμηλό επιτόκιο
• both words are in neuter singular

Because Greek adjectives must agree with the noun they describe.

Since επιτόκιο is neuter singular, the adjective must also be neuter singular:

• masculine: χαμηλός
• feminine: χαμηλή
• neuter: χαμηλό

So:

• το επιτόκιο είναι χαμηλό is correct because both noun and adjective match.

Είναι is the present-tense form of είμαι, meaning to be.

Here it means is:

• Το επιτόκιο είναι χαμηλό = The interest rate is low

A useful thing to know: είναι can mean both is and are, depending on the subject.

• Το επιτόκιο είναι χαμηλό = singular
• Τα επιτόκια είναι χαμηλά = plural

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

So:

• το επιτόκιο = the subject
• είναι = the verb
• χαμηλό = a predicate adjective describing the subject

One small detail: for neuter singular nouns, the article το looks the same in the nominative and accusative. So you identify the case from the role in the sentence, not from the article alone.

Yes. After είναι, Greek normally uses a predicate adjective that agrees with the subject.

So χαμηλό is:

• neuter
• singular
• nominative

It matches επιτόκιο.

Yes, Greek word order is more flexible than English, although the most neutral order here is:

Το επιτόκιο είναι χαμηλό.

You may also hear:

• Χαμηλό είναι το επιτόκιο.
• Είναι χαμηλό το επιτόκιο.

These alternatives are more marked and usually give extra emphasis to χαμηλό or to the whole statement. For a learner, the original version is the safest and most standard.

Normally, in a full everyday sentence, no.

Greek usually keeps the verb to be in sentences like this:

• Το επιτόκιο είναι χαμηλό.

You might see omission in:

• headlines
• notes
• very compressed style

But in normal speech and standard writing, keeping είναι is the normal choice.

Yes, Greek does have an indefinite article:

• masculine: ένας
• feminine: μια / μία
• neuter: ένα

So an interest rate would be:

• ένα επιτόκιο

That said, Greek does not always use the indefinite article in exactly the same way English uses a/an.
Ένα επιτόκιο είναι χαμηλό is grammatically possible, but depending on context it can sound like one / a certain interest rate is low rather than a broad general statement.

The plural is:

Τα επιτόκια είναι χαμηλά.

Changes:

• το → τα
• επιτόκιο → επιτόκια
• χαμηλό → χαμηλά
• είναι stays the same

So Greek shows the plural mostly through the article, noun, and adjective.

This is a very useful vocabulary distinction.

• επιτόκιο = interest rate
• τόκος = interest in the financial sense, usually the money charged or earned

So in your sentence, επιτόκιο is the correct word because you are talking about the rate, not the amount of interest itself.