Monitor je nad klávesnicí.

Je is the 3rd person singular form of the verb být (to be) in the present tense.

So:

• já jsem = I am
• ty jsi/jsi = you are
• on/ona/ono je = he/she/it is

Because monitor is a singular thing (it), Czech uses je:

• Monitor je... = The monitor is...

Nad means above, over, or higher than, depending on context.

In this sentence:

• Monitor je nad klávesnicí.
• The monitor is above the keyboard.

It describes physical position.

A useful comparison:

• na = on
• pod = under
• nad = above
• vedle = next to

Because the preposition nad here requires the instrumental case when it expresses location.

The dictionary form is:

• klávesnice = keyboard

But after nad in a location phrase, it changes to instrumental:

• nad klávesnicí = above the keyboard

So the ending changes from -e to -í.

This is very common in Czech:

• pod stolem = under the table
• před domem = in front of the house
• nad klávesnicí = above the keyboard

Not always, but very often.

With nad, the case depends on meaning:

• location → usually instrumental
• movement toward/over something → usually accusative

In your sentence, it is location, so Czech uses instrumental:

• Monitor je nad klávesnicí. = The monitor is above the keyboard.

Compare with movement:

• Dal monitor nad klávesnici.
• He placed the monitor above the keyboard.

Here nad klávesnici shows movement to that position.

Monitor is masculine inanimate.

Yes, gender matters in Czech because it affects:

• adjectives
• pronouns
• sometimes verb forms in the past tense
• case endings

In this sentence, gender does not change much on the surface because:

• monitor stays monitor
• the verb je is the same for all singular genders in the present tense

But in other sentences it matters more, for example:

• Ten monitor je nový. = That monitor is new.

Here ten and nový show masculine inanimate agreement.

Czech has no articles like English a/an/the.

So:

• Monitor je nad klávesnicí.

can mean:

• The monitor is above the keyboard.
• A monitor is above a keyboard.

Which meaning is intended depends on context. In many learning examples, English uses the because the objects are specific and already understood.

Yes, Czech word order is more flexible than English, but the most neutral order here is:

• Monitor je nad klávesnicí.

You may also hear:

• Nad klávesnicí je monitor.

This puts more focus on the location, almost like:

• Above the keyboard, there is a monitor.

So both are grammatical, but they may differ slightly in emphasis.

A helpful rough guide is:

• klá-ves-ni-tsí

Some pronunciation notes:

• á is a long a
• c in Czech is pronounced like ts
• í is a long ee

So klávesnicí sounds approximately like:

• KLAA-ves-ni-TSEE

Also:

• Monitor is pronounced roughly MO-nee-tor
• je is roughly ye

So the whole sentence sounds roughly like:

• MO-nee-tor ye nad KLAA-ves-ni-TSEE

Because Czech usually does not need a separate subject pronoun when the subject is already stated or understood.

Here the subject is explicitly named:

• Monitor

So adding a pronoun would be unnecessary.

Czech often omits pronouns even when English uses them:

• Je tam. = It is there / He is there / She is there, depending on context.

In your sentence, monitor already tells us what the subject is.

Yes. Monitor is a normal Czech noun, borrowed from international vocabulary, just like many technology words in many languages.

Czech also has plenty of native words, but borrowed words are very common, especially in technology.

So:

• monitor = monitor
• klávesnice = keyboard

No. That would be incorrect in standard Czech.

After nad expressing location, you need the instrumental case, so:

• klávesnice → dictionary form
• klávesnicí → correct after nad here

Correct sentence:

• Monitor je nad klávesnicí.

The basic forms are:

• monitor = monitor
• být = to be
• nad = above / over
• klávesnice = keyboard

In the sentence:

• je is a conjugated form of být
• klávesnicí is a case form of klávesnice

So if you look words up in a dictionary, use:

• monitor
• být
• nad
• klávesnice

If you want The monitors are above the keyboard, you would say:

• Monitory jsou nad klávesnicí.

Changes:

• monitor → monitory = monitors
• je → jsou = are

But klávesnicí stays instrumental singular if there is still only one keyboard.

If there were several keyboards:

• Monitory jsou nad klávesnicemi.
• The monitors are above the keyboards.