Overview

An introduction to the Irish copula 'is', used for identification, classification, and definition.

Copula Verbs Is Identification Classification

Irish has two verbs that translate as “to be”: the copula is and the substantive verb bí (usually seen in its present tense form, tá). This distinction is a core concept in Irish grammar and a common point of confusion for learners.

The copula is is used for permanent identification, classification, and definition. It answers the question “what is it?”. It links a subject to a noun or pronoun that defines what it is.

The substantive verb tá is used for describing temporary states, locations, and characteristics. It answers the question “how is it?” or “where is it?”.

Core Function: Identification and Classification

The copula’s main job is to state that one thing is another thing in a defining sense.

Is múinteoir mé. - I am a teacher.
Is Éireannach í. - She is an Irish person.
Is madra é sin. - That is a dog.

Watch out

Learners often mix up is and tá. Remember: use is to say what something is (a noun), and use tá to say how it is (an adjective) or where it is (a location).

`is` (The Copula)	`tá` (The Substantive Verb)
For identification (with a noun)	For description (with an adjective)
Is dochtúir í. (She is a doctor.)	Tá sí tinn. (She is sick.)
Is é an fear é. (He is the man.)	Tá an fear ard. (The man is tall.)
For classification (with a noun)	For location (with a preposition)
Is ainmhí an cat. (The cat is an animal.)	Tá an cat ar an mbord. (The cat is on the table.)

Sentence Structure

Copular sentences have a different structure from most other Irish sentences. The basic order is: Copula + Predicate + Subject.

The predicate is the noun that identifies or classifies the subject.

Is [predicate] [subject].
Is [múinteoir] [mé]. - I am a teacher.
Is [dochtúir] [Síle]. - Síle is a doctor.

When the predicate is a definite noun (i.e., it has the definite article an, a possessive adjective like mo, or is a proper noun), a pronoun (é, í, iad) must be inserted between the copula and the predicate.

Is é Seán an múinteoir. - Seán is the teacher.
Is í mo dheirfiúr í. - She is my sister.

Forms of the Copula

The copula has different forms depending on the tense and whether the sentence is a statement, a question, or a negative. Unlike regular verbs, it does not conjugate for person.

Context	Form	Mutation	Example
Present Affirmative	`is`	None	Is bean í. (She is a woman.)
Present Negative	`ní`	Lenition	Ní fear é. (He is not a man.)
Present Question	`an`	Eclipsis	An dochtúir tú? (Are you a doctor?)
Past Affirmative	`ba`	Lenition	Ba dhochtúir é. (He was a doctor.)
Past Negative	`níor`	Lenition	Níor dhochtúir é. (He was not a doctor.)
Past Question	`ar`	Lenition	Ar dhochtúir é? (Was he a doctor?)

These forms and their uses are covered in detail on the following pages.