Use of tanta and tantum

[pmda]

Hi, I wonder if anyone can throw light on this.

In Lingua Latina Chapter 8 there is the sentence:

Tanta gemma sola octoginta sestertiis constat.

which I take to mean this gem / jewel on its own costs 80 sestertii. My problem is with the word 'tanta' . This is an adjetive feminine nominative singular to agree with gemma, right - to mean something like 'only this' or 'as much'....

Then in the next sentence we have:

Medus: 'Num anulus sine gemma viginti tantum sestertiis constat?'

I take it to mean something like 'Is not the right without the jewel only 20 sestertii?'

Can anyone tell me is tanta used as adverb or is it declined here....and if so what's it agreeing with...?

[pmda]

Sorry I should have typed: 'Is not the RING without the jewel only 20 sestertii?

[loqu]

If I'm not wrong (and I may be), in that sentence 'tanta' works as an indefinite adjective. Thus it must agree with the noun it determines (gemma): tanta gemma sola constat LXXX sestertiis. I don't know how to translate it properly into English (not a native speaker), but it's along the idea of "such a great jewel itself costs 80 sestertii" (in fact, in the left column on that page it's explained, tanta = tam magna).

In the next sentence, I take 'tantum' to be an adverb thus it doesn't have to agree with anything.

[pmda]

Thanks...that's what I suspected..

[Imber Ranae]

An idiomatic rendering of the first sentence might be "A gemstone of such great size alone costs 80 sesterces." As loqu says, tanta agrees with gemma.

The adjective tantus,-a,-um suggests size (with countable nouns) or extent (with uncountable noun), usually with the positive connotation of largeness. However, it is technically relative and may, according to context, have the negative connotation of smallness. There's also the diminutive form tantulus,-a,-um which always means "so small, slight, insignificant".

It's only the adverb tantum that can mean "only" (the original idea being "to such a degree"), as in the second sentence. So...

Num anulus sine gemma viginti tantum sestertiis constat? means "Surely the ring without a gemstone does not cost only twenty sesterces?" Remember that num anticipates a negative answer.

[pmda]

Imber, thanks for this reply.