Role and Uses

An introduction to the Irish copula 'is', explaining what it is, when to use it, and how it differs from the verb 'bí'.

Copula Verbs Grammar Bí Vs Is

In Irish, there are two different words for the verb “to be”: bí and is. The word is is known as the copula. It is used to link a subject with a predicate that is a noun or a pronoun, essentially defining or classifying what the subject is. Understanding the difference between bí and is is a fundamental step in forming correct Irish sentences.

The Role of the Copula

The main job of the copula is to connect a subject to a noun or pronoun that describes it. This is different from the verb bí (which appears as tá in the present tense), which typically describes a state, condition, or location.

For example, to say “I am ill”, you use tá:

  • Tá mé tinn. - I am ill.

However, to say “I am a doctor”, you must use the copula is.

A common alternative that uses the verb bí involves turning the predicate into a prepositional phrase:

  • Tá mé i mo dhochtúir. - I am a doctor. (Literally: “I am in my doctor-ness.”)

Uses of the Copula

The copula is used in several common and important sentence structures.

Classification and Identification

This is the most common use of the copula, stating what something or someone is.

  • Is dochtúir é. - He is a doctor. (Classification)
  • Is é an dochtúir é. - He is the doctor. (Identification)

Adjectival Phrases

The copula is used with certain adjectives, particularly for subjective evaluations, comparisons, and in modal-like phrases.

  • Is maith sin! - That is good!
  • Is ionann iad. - They are the same.
  • Ba mhaith le Pól an carr a cheannach. - Paul would like to buy the car.
  • an fear is mó - the bigger/biggest man (literally, “the man who is bigger”)

Statements of Origin and Possession

It is used with prepositions like as, de, and le to show where something is from or who owns it.

  • Is as Corcaigh é. - He is from Cork.
  • Is le Pól an carr. - The car belongs to Paul.

Emphasis (Cleft Sentences)

The copula is essential for forming cleft sentences, which are used to emphasise a particular part of the sentence.

  • Is é an fear a dhéanann na bróga. - It is the man who makes the shoes.

Interrogative Questions

Questions that use an interrogative word (like “who?”, “what?”, “where?”) are formed using a copula construction, even if the copula itself is not visible.

  • Cé a rinne sin? - Who did that? (Literally: “Who is it that did that?”)

Key Grammatical Features

The copula follows a unique set of grammatical rules that distinguish it from regular verbs.

  • Limited Forms: It only has two basic forms: is for the present and future, and ba for the past and conditional.
  • Missing Forms: The copula has no imperative or verbal noun. To express these ideas, you must use a construction with bí and the preposition i.
    • Bí i d’fhear! - Be a man!
    • bheith ina fhear - to be a man
  • Invariable Forms: Copula forms do not change for person or number. is and ba are used for all persons (I, you, he, she, etc.).
  • Disjunctive Pronouns: The 3rd person personal pronouns sé, sí, and siad are not used directly after the copula. Instead, their disjunctive forms é, í, and iad are required.
  • Fused Forms: The copula merges with negative and interrogative particles. For example, ní is a fusion of ní + is (“is not”), and an is a fusion of an + is (“is it?”). Many interrogative words also contain an implied copula, e.g., cé (“who is?”).
  • Mutations: In the present tense, copula forms cause no mutation. In the past/conditional, the form ba always causes lenition.
  • Word Order: The word order in a simple copula sentence is Copula - Predicate - Subject.
  • Definite Nouns: A definite noun cannot come directly after the copula. It must be separated by a pronoun (é, í, or iad).
    • Is é an múinteoir an fear sin. - That man is the teacher.

Tenses of the Copula

  • is (Present/Future): This is the present tense form. While it can be used for the future (Is gearr gurb é - It will soon be), this is rare. For future classification, constructions with bí are more common. is is also used to introduce cleft sentences regardless of the tense of the main verb.
  • ba (Past/Conditional): This form is used for past tenses and the conditional. With noun predicates, it usually indicates the past. With adjective predicates, it can be past or conditional. In modal phrases, it is typically conditional.
    • Ba mhaith liom. - I would like.
  • gura/nára (Subjunctive): The form gura (negative nára) is used for the subjunctive mood, but this is uncommon in modern Irish.
Linguistic note: Fused forms and 'dropped' particles

The idea that forms like ní are “fusions” is a simplification. In reality, they are often the normal verbal particles, after which the copula is or ba is simply omitted. For example, ní is used instead of a theoretical *ní is*. This omission is why these particles do not cause lenition or eclipsis in the present tense (e.g., ní maith liom, not *ní mhaith liom*). In the past tense, although the form ba is also dropped, the lenition it would have caused is retained (e.g., níor mhaith liom). The trigger for lenition here is the “missing” ba, not the particle níor itself. True fusions include forms like más (from má + is) and those ending in -b or -bh, which are abbreviations of ba or bha (e.g., níorbh é an fear).

Historical note: The pronouns 'sé', 'sí', and 'siad'

From a historical perspective, the subject pronouns sé, sí, and siad are themselves considered to be combinations of the copula is and the older pronouns é, í, and iad. Following this logic, every sentence using these pronouns technically contains a copula linking the predicate and the subject.