Irish verb forms are constructed either synthetically or analytically.
Synthetic forms express the information about person and number in the ending: e.g., molaim "I praise", where the ending -aim stands for "1st person singular present". In this case, a pronoun is not allowed: *molaim mé is ungrammatical. Molann mé is allowed but using the -aim ending is more common.
Analytic forms are those whose endings contain no information about person and number, and a pronoun is necessary: e.g., molann sibh "you (pl.) praise", where the ending -ann expresses only the present tense, and the pronoun sibh "you" (pl.) must accompany it in order to express "2nd person plural".
In addition to the three persons, Irish also has an impersonal form (also called the "autonomous" form), which is used in forming the passive and can conveniently be translated with "one" or "someone" as the subject. Shown below are the distribution of synthetic and analytic forms in the standard language; in the dialects, other patterns may be found, although some of the most important distinctions made in certain dialects are pointed out in this article.
See Irish orthography for the pronunciation of verb endings.
There are two conjugation classes of regular verbs, as illustrated below. Forms in italics are not part of the standard language. The suffixes shown change to agree with the word ending in a velarised ("broad") consonant or palatalised ("slender") consonant. In the examples below, verbs ending with "broad" consonants are shown above those ending with "slender" consonants.
In the imperfect, preterite, and conditional, a consonant-initial stem undergoes lenition (and dialectally is preceded by do), while a vowel-initial stem is prefixed by d’. A stem beginning with ⟨f⟩ + a vowel takes both, e.g. fan "wait", d'fhan sé "he waited". The preterite impersonal, e.g. fanadh "one waited", neither undergoes lenition nor receives d'. The -⟨f⟩- in future and conditional stems is pronounced /h/; except in the conditional 2nd person singular and the impersonal, where it remains /f/.
Second stem verbs take the same base suffixes as first conjugation verbs, but add the infix in -⟨(a)í⟩- (most forms), or -⟨eo, ó⟩- (in the future and conditional).
Roots ending in a slender consonant undergo syncope before the addition of -⟨í⟩-.
There are eleven irregular verbs in Standard Irish; individual dialects have a few more. Most of them are characterized by suppletion, that is, different roots are used to form different tenses. Analytic forms are indicated by the symbol +. The preterites of many irregular verbs take the nonpreterite forms of preverbal particles, i.e. an (interrogative particle) and ní (negative particle), instead of ar (pret. interrogative particle) and níor (pret. negative particle). Some verbs have different independent and dependent forms in certain tenses; the independent forms are used when no particle precedes the verb, and also after má "if" (open conditional) and the direct relative particle a, while the dependent forms are used after all other particles.
The ⟨d⟩- in this verb's independent forms is not lenited, and the dependent forms are slightly archaic.
If a noun phrase is in the predicate, then forms of the particle "is" are used rather than anything below.
Clois is used in southern and south-central Irish (Munster, Connemara, Aran Islands etc.), whereas cluin is used in northern and north-central varieties (Mayo, Ulster).
The ⟨f⟩- in forms of this verb is eclipsed rather than lenited after ní.
The meaning "to be named" is often found in writings and can therefore be considered as strange for learners. When meaning "to be named" the verbform is usually followed by the preposition "ar", which is also inflected due to the person it is connected with. e.g.:
Irish uses a number of preverbal particles to modify the meaning of a sentence. In a positive statement, no particle is used and the verb comes first (except in Munster Irish where do is placed before verbs in the past, habitual past and conditional, leniting the verb that follows). This is still seen in the Standard Language in said tenses, prefixed to verbs beginning with vowels, e.g. d'ól mé (Munster Irish: d'ólas) "I drank":
To negate a statement, the particle ní is used, which causes lenition; a ⟨d’⟩ before a vowel or lenited ⟨f⟩ is omitted:
In the preterite, the particle níor is used . There is lenition but no d’.
(In Ulster, the negative particles cha(n), pret. char are also used)
To pose a simple yes/no question, the particle an is used, which causes eclipsis (no eclipsis of vowels, because an already ends with ⟨n⟩). In the preterite ar (+ lenition) is used. The prefix d’ is omitted:
These particles are also used to introduce an indirect question:
To pose a negative yes/no question, the particle nach is used, which causes eclipsis (in preterite: nár + lenition):
(In Munster ná is used instead of nach.)
To pose a wh-question, one of the interrogative particles cá, cad a/céard a, cathain a, cé a, conas a etc. is used.
Irish has no infinitive and uses instead the verbal noun. The verbal noun can be formed using different strategies (mostly suffixes). The most common of these are:
The verbal noun is used as the infinitive would be used in English.
A progressive can be expressed with the preposition ag and is equivalent to the English present participle.
A perfect tense can be formed with either of the compound prepositions tar éis or i ndiaidh and the verbal noun.
The subjunctive covers the idea of wishing something and so appears in some famous Irish proverbs and blessings. It is considered an old-fashioned tense for daily speech (except in set phrases) but still appears often in print. E.g.,
It is important to note that when the subjunctive is used in English, it may not be used in Irish, and another tense might be used instead:
While the relative pronoun that can be omitted in English, the corresponding go is mandatory in Irish.
