Mám jen jednu otázku.

Jedna otázka is the basic dictionary form (nominative singular, feminine): jedna (one) + otázka (question).

In this sentence, the noun is the object of the verb mám (I have), so Czech uses the accusative case:

• nominative: jedna otázka (one question – as the subject)
• accusative: jednu otázku (one question – as the object)

Because otázka is feminine:

• jedna → jednu in the accusative
• otázka → otázku in the accusative

So Mám jen jednu otázku literally: I-have only one-question (accusative).

Czech changes the noun ending according to grammatical case.

• otázka is nominative singular (used mainly for the subject of the sentence).
• After the verb mít (to have), the thing you have is in the accusative (direct object), so otázka changes to otázku.

Pattern (feminine noun ending in -a):

• nominative: otázka (subject)
• accusative: otázku (object: I have / I see / I ask … a question)

Czech has no articles (no equivalent of English a/an/the).

The word otázku can mean:

• a question
• the question
• or just question in general, depending on context.

So Mám jen jednu otázku naturally translates as I have only one question, even though there is no separate word for a.

• Mám – I have
• jen – only / just
• jednu – one (feminine, accusative)
• otázku – question (feminine, accusative)

Very literally: Have only one question (with I understood in the verb form).

In Czech, the subject pronoun (já – I) is usually dropped, because the verb ending already shows the person:

• mám = I have
• máš = you (sg.) have
• má = he/she/it has

You say:

• Mám jen jednu otázku. (I have only one question.)

You would add já only for emphasis or contrast:

• Já mám jen jednu otázku. – I (as opposed to someone else) have only one question.

Yes, you can say:

• Mám jen jednu otázku.
• Mám jenom jednu otázku.

Both are correct and mean the same: I have only one question.

jen and jenom are very close in meaning (only / just). jenom is a bit more colloquial and slightly longer/softer in speech, but in most everyday situations they are interchangeable.

Possible word orders and how they sound:

• Mám jen jednu otázku. – Neutral, most common: I have only one question.
• Mám jednu otázku jen. – Grammatically possible but unusual; could be used for special emphasis in speech or poetry.
• Jen mám jednu otázku. – Feels odd in standard Czech; jen usually comes right before what it limits (jednu otázku here), not before the verb.

So in natural speech, use:

• Mám jen jednu otázku.
  or
• Mám jenom jednu otázku.

You would say:

• Mám otázku. – I have a question.

This is fully correct. In practice, people often soften it a bit:

• Mám jednu otázku. – I have one question.
• Měl(a) bych otázku. – I would have a question. (more polite, conditional)
• Měl(a) bych jednu otázku. – I would have one question. (polite and common at the start of a question in meetings, classes, etc.)

Mám jen jednu otázku is polite enough in most everyday contexts (classroom, meeting, talking to a friend, informal presentation).

For a more formal / very polite tone, people often use the conditional:

• Měl(a) bych jen jednu otázku. – Literally: I would have only one question.
• Měl(a) bych jen jednu krátkou otázku. – I would have only one short question. (very polite/soft)

Using měl bych / měla bych makes it sound more respectful and less direct.

Both otázka and dotaz can mean question, but they differ slightly in use:

• otázka – the general word for a question; used in everyday speech, school, normal conversation.
• dotaz – also question, but often sounds a bit more formal or technical (e.g. in customer support, business, official communication).

You can say:

• Mám jen jednu otázku. – Very common, neutral.
• Mám jen jeden dotaz. – Also correct; sounds a bit more formal/official.

Note: otázka is feminine (jednu otázku), dotaz is masculine (jeden dotaz).

Approximate pronunciation with English-like hints:

• Mám – [maam] (long á like in father, but lengthened)
• jen – [yen] (short e as in get)
• jednu – [YED-noo]
• otázku – [oh-TAH-skoo]
  
  • o – like in more, but shorter
  • á – long a (like father, longer)
  • u – like oo in food

Stress is always on the first syllable of each word: MÁM jen JED-nu O-táz-ku.