G. J. Adler

“ D. Obs. The English idiom requires here id nōn habeō. In Latin, however, the pronoun is, ea, id is frequently omitted, when it would have to stand in the same case as the noun to which it relates. Of.—Ē, ex.
E. Obs. The preposition ē or ex is followed by the ablative. Ē can be put before consonants only, ex before vowels and consonants both. ”

“ Footnotes.
1 Nouns in l are generally neuter, but sometimes masculine.
2 Nouns which are sometimes masculine and sometimes feminine, according to the context, are said to be of the common gender. So adolēscēns and juvenis, m. & f., a young man or woman; conjūx, m. & f., a husband or a wife; īnfāns, m. & f., an infant; and a number of others. Nouns of which the gender is unsettled are said to be of the doubtful gender; as diēs, m. & f., a day; penus, m., f., & n., provisions.
3 Neuters ending in e, al and ar have ī in the ablative instead of e; as mare, marī; animal, animālī ”

“ F. Obs. The material of which anything is made may either be expressed by the ablative of a substantive with ē or ex, or by means of an adjective in eus. Thus:— Of the Genitive of the Third Declension. G. From the paradigms of this lesson it will be perceived, that substantives of this declension vary considerably as to the manner, in which they assume the characteristic termination of the genitive. The following rules are intended to give the learner some insight into the extent of this variation.5 Nouns in a change a into atis, as poēma, poēmatis, n., a poem. ”