[29.] 1. Descriptions of physical characteristics are expressed by the ablative with a modifying adjective. [§ 444].
2. Descriptions involving neither numerical statements nor physical characteristics may be expressed by either the genitive or the ablative with a modifying adjective. [§ 445].
[30.] The ablative is used to denote in what respect something is true. [§ 398].
[31.] The place from which is expressed by ā or ab, dē, ē or ex with the separative ablative. This answers the question Whence? Before names of towns, small islands, domus, and rūs the preposition is omitted. [§§ 264], [266].
[32.] Words expressing separation or deprivation require an ablative to complete their meaning. This is called the ablative of separation. [§ 180].
[33.] The word expressing the person from whom an action starts, when not the subject, is put in the ablative with the preposition ā or ab. This is called the ablative of the personal agent. [§ 181].
[34.] The comparative degree, if quam is omitted, is followed by the separative ablative. [§ 309].
[35.] The time when or within which anything happens is expressed by the ablative without a preposition. [§ 275].
[36.] 1. The place at or in which is expressed by the ablative with in. This answers the question Where? Before names of towns, small islands, and rūs the preposition is omitted. [§§ 265], [266].
2. Names of towns and small islands, if singular and of the first or second declension, and the word domus express the place in which by the locative. [§ 268].