You can't say that in english
That English is fine. It just depends on context. It would of course be better to say, 'any ketchup'.
So it seems that Greek doesn't have the 'sh' sound.
No, Greek doesn't have sounds like sh, ch, dzh(jeep) and zh(pleasure).
Who would say a sentence like that one???
'Ketsap' sound like Indonesia language, 'Kecap'
That's where it comes from
"Ketsap" here is the accusative case? It always looks like the nominative?
"κέτσαπ" is a loan word and doesn't change.