Timeglasset er tomt.

It is made of time + glas + -et.

• time = hour
• glas = glass
• timeglas = hourglass
• timeglasset = the hourglass

So Danish often builds compounds the same way English does.

The -et is the definite article attached to the noun. Danish usually puts the at the end of the noun instead of using a separate word.

• et timeglas = an hourglass
• timeglasset = the hourglass

This happens because timeglas is a neuter noun.

In Danish, nouns are either common gender or neuter.

• common gender: usually takes en
• neuter: takes et

Timeglas is a neuter noun, so:

• et timeglas
• timeglasset

Unfortunately, there is no fully reliable rule for guessing gender every time, so learners usually need to memorize it with the noun.

Because the adjective has to agree with the noun.

Since timeglasset is neuter singular, the adjective tom becomes tomt.

Compare:

• en tom flaske = an empty bottle
• et tomt glas = an empty glass
• timeglasset er tomt = the hourglass is empty

So the -t is the neuter singular adjective ending.

Because in a simple sentence like this, Danish normally just uses the noun with its attached definite ending:

• timeglasset = the hourglass

You would not usually say det timeglasset.

However, if there is an adjective before a definite noun, Danish often uses both:

• det tomme timeglas = the empty hourglass

That is a different structure.

Yes. Er is the present tense of at være = to be.

So:

• jeg er = I am
• du er = you are
• det er = it is

In Timeglasset er tomt, er means is.

This is the normal Danish word order for a basic statement:

subject + verb + complement

• Timeglasset = subject
• er = verb
• tomt = subject complement / adjective

So it works very much like English:

• The hourglass is empty

Not with the same meaning.

• tomt = empty
• tømt = emptied

So:

• Timeglasset er tomt = the hourglass is empty
• Timeglasset er tømt = the hourglass has been emptied

The second one suggests an action was done to it, while tomt just describes its state.

A helpful learner-friendly approximation is:

TEE-meh-glas-set

A few notes:

• time sounds roughly like tee-muh
• glas has a broad a sound
• -et in glasset is usually pronounced quite lightly

The whole sentence is said smoothly: Timeglasset er tomt.

In this sentence, tomt literally means empty. Since the subject is an hourglass, English might naturally understand the idea as the sand has run out or time is up, but the Danish word itself still means empty.

So the core meaning is physical emptiness, even if the context suggests a finished amount of time.

The indefinite version is:

Et timeglas er tomt.

That means: An hourglass is empty or A certain hourglass is empty, depending on context.

Compare:

• et timeglas = an hourglass
• timeglasset = the hourglass

Plural would be:

Timeglassene er tomme. = The hourglasses are empty.

Notice the changes:

• timeglasset → timeglassene = the hourglasses
• tomt → tomme = empty in plural

So adjective agreement changes in the plural too.