I-Stems: Ablative -ī [6/8]

We see that -im and tend to be common in the same words. That is, where -im is of frequency, so too is .

  • For more on where the -im ending shows up, see this post.
  • Beyond the contents of that post, the -ī ablative ending also appears:


1. with secūrī
2. with the adjectives (nominative -is) where these are used as nouns:

  • aequālī (a contemporary)
  • annālī (annals)
  • aquālī (washbasin)
  • cōnsulārī (former consul, member of the consular rank)
  • gentīlī (relative)
  • molārī (millstone)
  • prīmpīlārī (chief centurion)
  • tribūlī (fellow tribesman)

(As adjectives proper, they would be aequāle, annāle, etc. in the ablative.)

3. in the ablative of i-stem neuters (animālī, baccārī, etc.)


1. With the following nouns: avis, clāvis, febris, fīnis, īgnis, imber, lūx, nāvis, ovis, pelvis, puppis, sēmentis, strigilis, turris (definitions)

2. With the following adjectives (nominative -is or -ens) where they are used as substantives:

  • affīnī (son-in-law)
  • bipennī (battle-ax)
  • canālī (pipe)
  • familiārī (immediate family member)
  • nātālī (birthday, anniversary)
  • rīvālī (rival, competitor)
  • sapientī (wise man)
  • tridentī  (trident)
  • trirēmī (trireme)
  • vōcālī (vowel, vocalist (pl.))

(As adjectives, they would be affīne, bipenne, etc.)

Apparent Exceptions—

  1. The ablative of famēs (hunger) is always famē (not famī nor fame)
  2. The case defective māne (morning) is sometimes mānī (the word is found only in the ablative).
  3. Canis (dog) and iuvenis (youth) always take the ablative -e, never . (contrast with avisclāvis, etc.)

I-Stems: Masculine and Feminine Declension(s) [1/8]

As A&G note, “The i-stem was confused by even the Romans themselves.” There are a variety of variations with this stem present in all three grammatical genders, making it incredibly difficult to organize the data except in broad patterns and rote memorization. To that effective, I’m going to design a series of posts on the i-stem declension.

In this section, we’ll introduce the i-stem as a morphological class, and discuss the declension of ‘regular’ masculine and feminine i-stem nouns.

First off, all i-stems are either pure or mixed.

Most pure i-stems are immediately identifiable by their lexical entry, because they feature parisyllabic  (having the same number of syllables) nominative and genitive forms. This is true of masculine, feminine and neuter i-stem nouns. However, most masculine and feminine nouns also have nominative and genitive forms that are completely identical. Let’s take a look:

sitis, sitis (f.) thirst (declined only in the singular, for sensible reasons)

Picture 1

ignis, ignis (m.) fire

Picture 2

A few unique features to note:

  • nominative singular -is (except in four cases, see below)
  • accusative singular –im (though not always)
  • ablative singular (though not always)
  • genitive plural -ium (strictly)

As you can see, there aren’t many markers (just one) that guarantee any given noun is an i-stem noun. In fact, it would be possible to decline ignis in a way such that only it’s nominative singular and genitive plural gave any hint of the i-stem status.

With four nouns in particular (imber, rain; linter, skiff; ūter, wineskin; venter, belly) this problem is even more evidence because here even the nominative is lost as a distinctive feature. The only morphological form that demonstrates imber‘s i-stem status is its genitive plural imbrium.

So to review masculine and feminine i-stem declension: difficult, difficult, difficult. As we’ll see, the neuter declension isn’t much easier…

The essential AG: 66-7.