Az összeg alacsony.

A and az are both the Hungarian definite article, meaning the.

• Use az before a vowel sound.
• Use a before a consonant sound.

Since összeg begins with ö, you say az összeg.

Examples:

• az összeg = the amount
• a szám = the number

In Hungarian, the verb to be is often omitted in the present tense, third person, when the sentence links the subject to a noun or adjective.

So:

• Az összeg alacsony. literally looks like The amount low.
• But it naturally means The amount is low.

This is normal Hungarian grammar.

Compare:

• Az összeg alacsony. = The amount is low.
• Az összeg alacsony volt. = The amount was low.
  Here volt appears because it is past tense.

Because here alacsony is not directly describing the noun inside a noun phrase; it is the predicate of the sentence.

So:

• Az összeg alacsony. = The amount is low.
• az alacsony összeg = the low amount

This is an important difference:

• adjective after the noun in this kind of sentence = is low
• adjective before the noun = low amount

Yes. That is also correct.

Both are grammatical, but the emphasis changes:

• Az összeg alacsony. = neutral statement, The amount is low.
• Alacsony az összeg. = more emphasis on low, something like The amount is low or It’s the amount that is low.

Hungarian word order is flexible, and changing the order often changes what is being emphasized.

Hungarian has no grammatical gender, so there is no masculine/feminine agreement to worry about.

For number:

• with a singular subject: Az összeg alacsony.
• with a plural subject: Az összegek alacsonyak.

So in predicate position, the adjective can show plural.

But when the adjective is directly before the noun, it usually does not take a plural ending:

• az alacsony összegek = the low amounts

So:

• Az összegek alacsonyak. = The amounts are low.
• az alacsony összegek = the low amounts

Összeg usually means amount or sum.

Depending on context, it can refer to:

• an amount of money
• a total
• the result of addition in math

So it is a fairly broad word. In this sentence, it most naturally means amount or sum.

It can definitely be used for amounts, levels, prices, and similar things.

So alacsony can mean:

• short for a person or object
• low for a level, amount, price, temperature, etc.

Examples:

• A fiú alacsony. = The boy is short.
• Az ár alacsony. = The price is low.
• Az összeg alacsony. = The amount is low.

Yes, a few useful ones:

• ö in összeg is a vowel that does not exist in standard English. It is similar to German ö or French eu in some words.
• sz in Hungarian is pronounced like English s.
• In összeg, the spelling ssz represents a long s sound.
• cs in alacsony is pronounced like English ch.
• ny in alacsony is like the ny sound in canyon for many English speakers.
• Stress in Hungarian normally falls on the first syllable of each word.

So the main thing to remember is that Hungarian spelling is quite regular, but some letter combinations do not match English expectations.