Ten test jest łatwiejszy niż wczorajszy.

Because test is a masculine singular noun in Polish, and the demonstrative ten has to agree with it in gender, number, and case.

The basic nominative forms are:

• ten for masculine nouns
• ta for feminine nouns
• to for neuter nouns

So:

• ten test
• ta książka
• to zadanie

Here, test is masculine, so ten is the correct form.

It is in the nominative singular.

Why?

• test is the subject of the sentence
• subjects are normally in the nominative
• ten matches test, so it is nominative too

So:

• ten = nominative masculine singular
• test = nominative masculine singular

Łatwiejszy is the comparative form of łatwy.

• łatwy = easy
• łatwiejszy = easier

Polish often forms comparatives by adding endings such as:

• -szy
• -ejszy
• -iejszy

But the stem may also change a little, so the comparative is not always perfectly predictable from the base adjective.

Here:

• łatw- becomes łatwiejsz-
• final form: łatwiejszy

This is something learners usually memorize as a whole form:

• łatwy → łatwiejszy

Because the adjective must agree with the noun it describes: test.

Since test is:

• masculine
• singular
• nominative

the adjective also has to be:

• masculine
• singular
• nominative

So the form is:

• łatwiejszy test

Compare:

• łatwiejszy test — masculine
• łatwiejsza książka — feminine
• łatwiejsze zadanie — neuter

Even though the adjective comes after jest, it still agrees with test.

Jest is the 3rd person singular form of być (to be), so it means is.

The sentence structure is:

• Ten test = subject
• jest = is
• łatwiejszy = easier
• niż wczorajszy = than yesterday’s

So jest connects the subject with the description, just like English is.

In normal standard Polish, jest is the expected form here.

Niż is a standard word used after a comparative, meaning than.

So:

• łatwiejszy niż... = easier than...

You may also see od used with comparatives in Polish, but the structure changes slightly.

For example:

• Ten test jest łatwiejszy niż wczorajszy.
• Ten test jest łatwiejszy od wczorajszego testu.

Both are correct, but they are built differently:

• niż often keeps a more direct than structure
• od usually requires the following noun phrase in the genitive

That is why with od, you get wczorajszego testu, not wczorajszy.

Because Polish can omit a noun when it is obvious from context.

Here, wczorajszy really means:

• wczorajszy test = yesterday’s test

Since test has already appeared earlier in the sentence, Polish naturally leaves it out:

• Ten test jest łatwiejszy niż wczorajszy.

This is very natural and common. English does something similar:

• This test is easier than yesterday’s.

So wczorajszy is functioning like yesterday’s one / yesterday’s test.

Wczorajszy is an adjective meaning yesterday’s or from yesterday.

It comes from wczoraj (yesterday), but it behaves like a normal adjective and changes form to match the noun.

Examples:

• wczorajszy test — yesterday’s test
• wczorajsza lekcja — yesterday’s lesson
• wczorajsze zadanie — yesterday’s task

In your sentence, the noun is omitted, but the adjective still appears in the form that matches the understood noun test, so it stays wczorajszy.

Because it stands in place of wczorajszy test.

Even though test is omitted, it is still understood, and wczorajszy must match it.

Since the understood noun is:

• masculine
• singular
• nominative

the adjective is also:

• masculine
• singular
• nominative

That is why you get:

• niż wczorajszy

not:

• niż wczorajszego
  unless you use a different structure, such as with od

Yes, Polish word order is more flexible than English, but not every version sounds equally neutral.

The most neutral version here is:

• Ten test jest łatwiejszy niż wczorajszy.

You could change the order for emphasis, but that may sound more marked or stylistic.

For example, putting łatwiejszy earlier would usually add emphasis. A learner should first stick with the neutral order:

• Ten test
  • jest
    • łatwiejszy
      • niż wczorajszy

That is the safest and most natural pattern.

No, not in standard Polish.

Because test is masculine, the correct demonstrative is ten, not to.

• ten test = this test
• to is used with neuter nouns, or in other structures such as To jest...

For example:

• To jest test. — This is a test.
• Ten test jest łatwiejszy. — This test is easier.

So to and ten are both common words, but they are used in different constructions.

In normal Polish, łatwiejszy is the natural and correct choice.

Polish generally prefers a synthetic comparative for common adjectives:

• łatwy → łatwiejszy
• trudny → trudniejszy
• szybki → szybszy

Using bardziej + adjective is possible in some cases, especially with adjectives that do not easily form a simple comparative, but for łatwy, bardziej łatwy sounds unnatural compared with łatwiejszy.

So learners should use:

• łatwiejszy

These two words can be tricky because of the consonant clusters.

A few helpful points:

• ł sounds roughly like English w
• cz sounds like ch in chop
• sz sounds like sh
• j sounds like English y

So roughly:

• łatwiejszy ≈ wat-VYEY-shy
• wczorajszy ≈ fcho-RAI-shy or vcho-RAI-shy depending on how carefully you pronounce the initial cluster

You do not need a perfect English imitation, but it helps to notice:

• łatwiejszy has -wiej-
• wczorajszy has wcz-, which is a dense cluster for English speakers

The best approach is to learn them as whole sound patterns rather than letter by letter.

Yes.

• Ten test jest łatwiejszy niż wczorajszy. = This test is easier than yesterday’s.
• Test jest łatwiejszy niż wczorajszy. = The test is easier than yesterday’s or just A test is easier than yesterday’s, depending on context

Polish does not have articles like the or a, so test by itself can often mean the test if the context makes it clear.

Using ten makes it more explicitly this test.