Ležím na zádech.

Ležím is the 1st person singular present tense of the verb ležet, which means to lie or to be lying.

So ležím means I lie / I am lying.

In Czech, the present tense often covers both:

• I lie
• I am lying

The ending -ím tells you it is I.

Czech often drops personal pronouns when they are not needed.

Because ležím already means I am lying, adding já is usually unnecessary.

So:

• Ležím na zádech. = I’m lying on my back.
• Já ležím na zádech. is possible, but já adds emphasis, like:
  • I’m the one lying on my back.
  • Me, I’m lying on my back.

This is very normal in Czech.

Because záda is a special noun: it is normally used only in the plural in Czech.

Even though English usually says back in the singular, Czech says záda, literally something like backs, but it functions as the normal word for back in the body sense.

After the preposition na in this meaning, the noun goes into the locative case, so:

• basic form: záda
• locative plural: na zádech

So na zádech is the correct form for on one’s back.

Zádech is in the locative plural.

The preposition na can take different cases depending on meaning:

• na + accusative often means movement onto something
• na + locative often means location on something

Here there is no movement. The sentence describes a position:

• Ležím na zádech. = I am lying on my back

So Czech uses na + locative:

• na zádech

A useful contrast:

• Lehnu si na záda. = I will lie down onto my back / I’ll roll onto my back
  
  • movement, so accusative
• Ležím na zádech. = I am lying on my back
  
  • location/state, so locative

For the body part meaning back, yes, it is generally treated as a plural-only noun.

You will commonly see forms like:

• bolí mě záda = my back hurts
• na zádech = on one’s back
• do zad = into the back
• za zády = behind someone’s back

So this is one of those nouns where English and Czech organize the idea differently.

A simple learner-friendly pronunciation guide is:

LE-zheem na ZAA-dekh

A bit more precisely:

• Ležím: the ž sounds like the s in measure
• zá is long, so hold the á a little longer
• ch in zádech is the rough Czech ch sound, like in German Bach or Scottish loch

Stress in Czech is usually on the first syllable of each word:

• LE-žím
• na
• ZÁ-dech

Yes. Czech word order is more flexible than English word order.

The neutral, natural sentence is:

• Ležím na zádech.

But other word orders are possible for emphasis or context, for example:

• Na zádech ležím.
• Já ležím na zádech.

These do not usually change the basic meaning, but they can shift the focus:

• Ležím na zádech. = neutral statement
• Na zádech ležím. = emphasis on on my back
• Já ležím na zádech. = emphasis on I

For beginners, Ležím na zádech is the best default version.

This is a very common Czech question because English often uses lie for both ideas.

Czech distinguishes between:

• ležet = to be lying, to already be in that position
• lehnout si = to lie down, to move into that position

So:

• Ležím na zádech. = I am lying on my back.
• Lehnu si na záda. = I will lie down on my back / I’ll lie onto my back.

This is a common Czech pattern:

• one verb for the state
• another verb for the movement into the state

Usually, if you want to say that you are physically lying on your back, Ležím na zádech is the normal choice.

Jsem na zádech can exist, but by itself it does not sound as specifically natural for the physical posture. It can also have other meanings depending on context, including figurative ones.

So for the body position, use:

• Ležím na zádech.

That is the most direct and idiomatic sentence.

You can build similar sentences with other body-position expressions:

• Ležím na břiše. = I’m lying on my stomach.
• Ležím na boku. = I’m lying on my side.

So the pattern is very useful:

• Ležím na zádech.
• Ležím na břiše.
• Ležím na boku.

These are common everyday expressions.

No. Na zádech is a general expression meaning on one’s back, so it can be used with other verbs too.

For example:

• Spím na zádech. = I sleep on my back.
• Plaval na zádech. = He swam on his back.
• Otočil se na záda. = He turned onto his back.
  
  • notice that with movement, Czech often switches to na záda

So the phrase itself is very useful beyond this one sentence.