Parsing a present perfect participle

Question

I just started learning Latin and am currently reading roma aeterna and came across the following sentence:

Romani cotidie in thermas illas celebres lavatum eunt

AFAIK this could mean both:

1. The washed Romans daily go to those famous thermal baths
2. The Romans will daily be washed in those famous thermal baths

In 1 I read it as a seperate PPP and a declined form of ire (lavatum being PPP and eunt being the finite verb form of ire)

In 2 I read it as the future passive infinitive of lavare (lavatum eunt)

Is one of these translations correct (since they don't seem to be, given the context)?

What am I not seeing or misunderstanding here?

Answer 1

Lavatum here isn't a perfect passive participle, but a supine. When it's accusative (ends in -um) and is coupled with a verb of motion (here eunt, "they go"), it expresses purpose.

Here's a link that shows the use of the supine, and if you want, here's Allen and Greenough's section on the topic.

So, the actual translation is:

Romani cotidie in thermas illas celebres lavatum eunt

The Romans every day go into those famous warm springs to wash [their bodies].

Answer 2

In addition to cmw's answer, both of your interpretations are unworkable as the Latin text stands:

Your first interpretation (“the washed Romans”) cannot be true because lavatum does not agree with Romani (that would be lavati). If it was lavati, then it would have to be a perfect participle, because the supine is undeclinable and always ends in -um. (Calling this the accusative is historically correct, but it is not very useful to think of it as an accusative form.)

Regarding your second reading (“the Romans will be washed”), the future passive infinitive would be: lavatum iri. Now that you know the supine and the fact that it goes with verbs like ire, you may recognise that it is in fact the supine that's used in this form. although in practice the future passive infinitive is a weird special form that's nigh impossible to understand from its constituents.

However, the so-called future passive infinitive is a periphrastic form that exists because there is no real future passive infinitive. For the finite forms, there is no such need—they are just the ordinary forms of the future passive; in this case that would be lavabuntur.