[2586.] (1.) In the early dramatists, substitutions are very numerous, and lines which follow the normal scheme are rare. Substitutions are most frequent in the first foot.

[2587.] (2.) Four shorts rarely stand in succession unless they belong to the same foot. Hence a dactyl or tribrach is seldom followed by an anapaest.

[2588.] (3.) The dactyl and proceleusmatic are rare in the fifth foot. The proceleusmatic occurs chiefly in the first foot.

[2589.] (4.) The fifth foot is very often a spondee. It must not be a pure iambus except (a.) when the line ends with a polysyllable of four or more syllables; (b.) when it ends with a word which forms a Cretic ([2521]); (c.) when it ends with an iambic word preceded by one which forms a Fourth Paeon ([2521]), or by an anapaestic word which is itself preceded by a final short syllable; (d.) when there is a change of speakers before the last foot; (e.) when elision occurs in the fifth or sixth foot.

[2590.] (5.) The main caesura is rarely preceded by a monosyllable.

[2591.] (6.) In the Senarius, and in the other iambic and trochaic verses of the early dramatists, a resolved arsis or thesis is usually placed so that its first syllable begins a word, or so that the two shorts of the resolved arsis or thesis are enclosed by other syllables belonging to the same word. Hence a dactylic word with the ictus on the penult or ultima (e.g. tempóre) rarely occurs. But there are occasional exceptions to the rule, especially in the case of words that are closely connected (e.g. a preposition with its case).

(B.) Later Period.

[2592.] Later writers conform more closely to Greek usage, but differ from one another in the degree of strictness with which they follow it. The general scheme is:

⏑͐ –́⏑ –̇⏑͐ ‖ –́⏑ –̇⏑͐ –́⏑ –̇
⏑ ⏑́ ⏑⏑ ⏑̇ ⏑⏑ ‖ ⏑́ ⏑⏑ ⏑̇ ⏑⏑ ⏑́ ⏑
> ⏑́ ⏑ > ‖ ⏑́ ⏑
[⏑ ⏑ –́][⏑ ⏑ –̇]
[⏑ ⏑ ⏑́ ⏑]

The main caesura is usually the penthemimeral ([2544]). The hephthemimeral sometimes occurs, but usually in connection with the penthemimeral, or with a diaeresis after the second foot. If the hephthemimeral is used without either of these, the second and third trochees of the line must form one word, as in