At least Italian and French have an idiomatic way to say "I have only one friend":

• Non ho che un amico.
• Je n'ai qu'un ami.

Finnish has the same thing: "Minulla ei ole kuin yksi ystävä." I can't think of a parallel way to phrase it in English. ("I have but one friend" is perhaps closest.) Is there something comparable in Latin?

I can express the same though in Latin easily enough: unum solum amicum habeo or similarly with possessive dative. But this is structurally quite different, and I am specifically after the structure. Is there something like non habeo quam unum amicum, which corresponds quite literally to the three ones given above?

What would be the closest Latin equivalent to the construction in Italian and French? I assume a similar thing is found in many Romance languages and they descend from Latin. The closest I can think of is nihil habeo nisi unum amicum, but perhaps there is something closer.