The Irish demonstratives ‘seo’ and ‘sin’

The English words this, that, these and those are called demonstratives because they, well, demonstrate whether you are talking about something that is "here" (this, these) or "there" (that, those). They can be used in combination with a noun (this man, those boxes) or on their own (this is funny, those are mine).

The Irish equivalents are:

• seo for both this and these,
• sin for both that and those.

There is also a third one, úd/siúd, but we have a separate minilesson about that one. This minilessons summarizes pretty much everything you need to know about seo and sin.

Using seo and sin with nouns

In English, when you have a noun phrase such as the man and when you want to add a demonstrative to it, you replace the article with it: this man, that man.

In Irish, you leave the article in its place and add the demonstrative after the noun.

an fear  the man

and fear seo  this man

an bhean  the woman

an bhean sin  that woman

na fir  the men

na fir seo  these men

na mná  the women

na mná sin  those women

Using seo and sin with long noun phrases

If the noun is modified by one or more adjectives, you place the demonstrative at the end of the whole thing:

an teach mór  the large house

an teach mór seo  this large house

an tír bhocht chráite  the poor troubled country

an tír bhocht chráite seo  this poor troubled country

The same positioning (at the end of the whole thing) is used when the noun is modified by another noun:

an siopa caife  the coffee shop (literally the shop of coffee)

an siopa caife seo  this coffee shop

an bosca poist  the post box (literally the box of post)

an bosca poist seo  this post box

When the noun is modified by an adverb or by something that begins with a preposition, then the demonstrative is normally placed before the adverb or preposition (and not at the end of the whole thing):

an cat faoin tábla  the cat under the table

an cat sin faoin tábla  that cat under the table

an fear thuas  the man up there

an fear sin thuas  that man up there

Notice that the demonstratives are always accompanied by the definite article. Together, they surround the noun phrase. The only exception is when the noun phrase is definite but does not begin with an article, which can sometimes happen on account of the double-article-avoidance rule:

teach an mhúinteora  the teacher's house (literally house of the teacher)

i ngleann na ndeor  in the valley of tears (literally in valley of the tears)

To add a demonstrative to this, you simply insert it at the end of the head noun phrase:

teach seo an mhúinteora  this teacher's house

i ngleann seo na ndeor  in this valley of tears

Using seo and sin on their own

When you want to use a demonstrative without a noun, as in this is funny or those are mine, there are two ways to do this in Irish.

One way is together with a pronoun:

tá sé seo greannmhar  this is funny

ní maith liom é seo  I don't like this

is liomsa iad sin  those are mine

Another way is to leave the pronouns out:

tá seo greannmhar  this is funny

ní maith liom seo  I don't like this

The former method (with pronouns) is more common. It is also less ambiguous: because you have the pronoun there, you know whether you are talking about something plural or something singular and, in the singular, you know what gender it is. This comes in handy when talking about people because you can refer to them non-committally by gender without having to use a specific noun:

cé hí sin?  who is that (woman, lady, girl...)?

cé hé seo?  who is this (man, guy, dude, boy...)?