I have recurring difficulty with ‘decet’. In Orberg LLPSI Cap III he has: Nec enim quidquam nisi argentum mensam decet viri nobilis.
Does ‘deceit’ have a subject? Is ‘viri nobilis’ genitive? How does the syntax work. I know what It means but can’t figure out how it works.
Nor is it fitting that anything other than silver adorn the table of a rich man.
Decet is usually an impersonal verb, i.e., it has as its subject only a vague “it”, as in the English saying “it is raining” (what is raining exactly? the clouds? the sky? no — “it” is). As an impersonal verb it means “it is proper/fitting for”. Vōs decēbit nihil dīcere. “It will be fitting for you to say nothing.”
Here, it is not impersonal: it has a specific, stated subject, nec quidquam nisi argentum. To translate it literally: “For nothing except silver befits/adorns the table of a notable man.”
You can see those two ways of using decet as being really the same if you treat the infinitive as a noun (when used as a noun, the infinitive is regarded as neuter singular):
Vōs decēbit nihil dīcere.
It will be fitting for you to say nothing = Saying nothing will suit you.
To say nothing, saying nothing: subject - nihil dicere
will be appropriate for, will suit: verb - decebit
you: object - vos
Many thanks to you both.