Salteaua este ușoară.

Because -ua here shows the definite article in Romanian.

• saltea = a mattress
• salteaua = the mattress

Romanian usually puts the at the end of the noun instead of using a separate word like English does.

So:

• Salteaua este ușoară. = The mattress is light.

Saltea is a feminine noun.

That matters because the adjective must agree with it:

• masculine singular: ușor
• feminine singular: ușoară

Since salteaua is feminine singular, the sentence uses:

• ușoară

So salteaua este ușoară is grammatically matched: feminine noun + feminine adjective.

This is adjective agreement.

In Romanian, adjectives often change form to match the noun’s:

• gender
• number
• sometimes definiteness context, depending on structure

Here the important part is gender and number:

• ușor = masculine singular
• ușoară = feminine singular

Examples:

• un pat ușor = a light bed
• o saltea ușoară = a light mattress

So ușoară is used because salteaua is feminine singular.

Here, ușoară means light in weight, meaning not heavy.

So the sentence means:

• The mattress is light.

The adjective ușor / ușoară can also mean easy in other contexts, but in this sentence, with mattress, the natural meaning is light rather than easy.

Este means is.

It is the 3rd person singular of the verb a fi = to be.

So:

• salteaua = the mattress
• este = is
• ușoară = light

In standard Romanian, you normally keep este in this kind of sentence.

In informal speech, people often say:

• Salteaua e ușoară.

Here e is a short spoken form of este. Both are correct, but este may sound a bit more neutral or careful.

This is the normal Romanian pattern:

• subject + verb + adjective

So:

• Salteaua = subject
• este = verb
• ușoară = predicate adjective

Romanian word order is often fairly flexible, but this is the most straightforward and neutral order.

A simple English-friendly approximation is:

• sahl-TEH-wah

A few notes:

• tea here sounds roughly like te-a, not like English tee
• the ending -ua is pronounced as two vowels together
• the stress is usually on -tea-

So it sounds roughly like sahl-TEH-wah.

A rough approximation is:

• oo-SHWAH-ruh

Helpful details:

• ș sounds like English sh
• ă is a short central vowel, something like the a in sofa
• oa forms a diphthong, so șoa sounds somewhat like shwa

So:

• ușoară ≈ oo-SHWAH-ruh

Not exact, but close enough for a learner.

Because Romanian usually uses a postposed definite article, meaning the article is attached to the end of the noun.

Compare:

• English: the mattress
• Romanian: salteaua

This is one of the big differences between Romanian and English.

With this noun:

• saltea = mattress / a mattress
• salteaua = the mattress

Yes, but it means something slightly different.

• O saltea este ușoară. = A mattress is light.
• Salteaua este ușoară. = The mattress is light.

The first is indefinite, the second is definite.

In many situations, O saltea este ușoară may sound less natural by itself unless you are making a general or contrastive statement. The definite version often sounds more natural if you are talking about a specific mattress.

It would usually use the masculine form ușor.

For example:

• Patul este ușor. = The bed is light.

Compare:

• Salteaua este ușoară. = feminine
• Patul este ușor. = masculine

This is a useful way to see adjective agreement clearly.

Romanian often drops subject pronouns like eu, tu, el, because the verb form already gives useful information. But here the subject is a noun, not a pronoun, and it carries the main meaning.

So you would not normally drop salteaua if you want to say The mattress is light.

You can shorten only the verb form in casual speech:

• Salteaua este ușoară.
• Salteaua e ușoară.

But the noun itself stays unless the context already makes it completely obvious and you are answering very briefly.