Are the following correct?

go dtí an pháirc
go dtí an bóthar

If so, it looks like "go dtí an" doesn't work with the dative at all!

I thought that "go" changed to "go dtí an" when you tried to put "an" after it, but I've also seen it used simply like:

Chuaigh sé go dtí Sasanna

What's up with that?

quote:

If so, it looks like "go dtí an" doesn't work with the dative at all!

Yes, it works with nominative case (an tuiseal ainmneach).
"Go dtí" etymologically isn't a real preposition because "tí" is an old subjunctive of "tar" (= come).
"go dtí X", literary: "until X comes"
X is subject of "tí / come".

quote:

I thought that "go" changed to "go dtí an" when you tried to put "an" after it, but I've also seen it used simply like:

Chuaigh sé go dtí Sasanna

What's up with that

Usually you use "go" without "an ...".
But you use always "go dtí" with "an ...".

Lars

As for the habit to say "go dtí Sasana" instead of just "go Sasana", although it is frowned upon by grammarians, this habit certainly exists, even among fluent native speakers.

My theory is that we are witnessing language change in progress here. The use of "go dtí" is spreading from nouns with the definite article to all definite nouns, with or without an article.

Oh and by the way, several other prepositions are also "exempt" from the dative case and are used with the nominative instead. Beside "go dtí", they are:

gan, without (gan an t-aisteoir)
seachas, except (seachas an bhean)
idir, between (idir an bhean agus an fear)
murach, "if it wasn't for" (murach an clár plé seo)

There may be a few others that I can't think of right now.

And then there is a whole open set of prepositions which are used with the genitive, most are multi-word items like "le haghaigh" and "i gcoinne" but there is at least one single-word one, "trasna", across (trasna na sráide). But you probably knew that.