Learn Spanish (Latin America): No quiero que el ciudadano tenga un problema. - I don't want the citizen to have a problem.

Tenga is the present subjunctive form of tener. We use the subjunctive here because the first part of the sentence (No quiero que...) expresses a wish or desire about someone else. Tener is irregular in the subjunctive: it takes its stem from the 'yo' form (tengo), so the subjunctive form becomes tenga.

In English we say 'I don't want the citizen TO HAVE'. Why does the Spanish sentence use que and a conjugated verb?

In Spanish, when you want someone else to do something, you can't just use the infinitive (like tener). Instead, you must use que (that) followed by a new clause with a subjunctive verb. You are literally saying, 'I don't want that the citizen has a problem.'

Why is it un problema and not una problema if the word ends in 'a'?

Even though it ends in '-a', problema is a masculine noun. Many Spanish words that end in -ema or -ama (like el programa or el sistema) are masculine because of their Greek origins. You will always use el or un with problema.

Does ciudadano change if the citizen is female?