"An samhradh seo."

Translation: This summer.

[DejanRumpf]

Would it be wrong to assume, based on this example, that the words "seo" and "sin" are always used with the preceding "an"? Should it be: "Tá an óiche seo go hiontach" or could you also say "Tá óiche seo go hiontach"?
The first one seems more logical to me, but just to be sure... I can't find the rule anywhere.

[SatharnPHL]

To say "this X" or "that Y", you need the definite article in Irish - an X seo or an Y sin.

seo and sin can be used without a definite article, but in slightly different contexts - Cé a rinne sin? - "Who did that?", bí ag faire air seo - "watch this space" (be looking at this), ní bheidh sé seo éasca - "this won't be easy".

[KarenSpark5]

How do you know whether it is 'seo' or 'sin'?

[SatharnPHL]

an samhradh seo - "this summer"
an samhradh sin - "that summer"

[JohanaSchw]

this masculine s noun in the definite nominative does not need t-

[Codester3]

I’m curious about the way she pronounces “seo” here.

When we were introduced to the word early on, it was pronounced like “show” (like a movie or a play). This time, it sounded more like “shuh” (as in “shut the door”, but without the “t”).

Are there different ways that it’s commonly pronounced, depending on the use? For example, in American English, the word “the” is commonly pronounced “thuh”, or even just “th” when we’re in a hurry.