READ OUT LOUD. Choose which marked text you prefer to practice with - macrons in verse form, or macrons in prose order, or accent marks in prose order, or focusing on the meter. You will find materials for all of these options below. :-)
VERSE MACRONS. Here is the verse text with macrons:
Fortibus afflictīs, generōsī, parcite, cīvēs!
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Bōs celerī passū cupiēns fūgisse Leōnem
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Cornibus adversīs et proelia fronte gerēbat;
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"Nōn tua frōns horrenda mihī, nōn, improbe, cornū.
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Bellua sī longē, quam tū plūs fortis, abesset,
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PROSE MACRONS. Here is the same text with macrons written out in prose word order:
Cīvēs generōsī, fortibus afflictīs parcite! Turpe nocēre fuit quōs Fortūna premit. Bōs celerī passū Leōnem fūgisse cupiēns Hircō obvius est; Hircus viā cōnstitit; fronte et cornibus adversīs proelia gerēbat; cuī Bōs fugitīvus rapidīs verbīs ait: "Improbe! Tua frōns nōn mihī horrenda, tuum cornū nōn horrendum. Iste Leo, quī me sequitur, sōlus territat. Sī bellua, plūs fortis quam tū, longē abesset, mox humus sanguine vestrō sparsa fuisset."
STRESS (ACCENT) MARKS. Here is the prose text with accents, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Cives generósi, fórtibus afflíctis párcite! Turpe nocére fuit quos Fortúna premit. Bos céleri passu Leónem fugísse cúpiens Hirco óbvius est; Hircus via cónstitit; fronte et córnibus advérsis próelia gerébat; cui Bos fugitívus rápidis verbis ait: "Ímprobe! Tua frons non mihi horrénda, tuum cornu non horréndum. Iste Leo, qui me séquitur, solus térritat. Si béllua, plus fortis quam tu, longe abésset, mox humus sánguine vestro sparsa fuísset."
ELEGIAC COUPLET METER. Below I have used an interpunct dot · to indicate the metrical elements in each line, and a double line || to indicate the hemistichs of the pentameter line.
Fortibus· afflic·tīs, gene·rōsī,· parcite,· cīvēs!
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Bōs cele·rī pas·sū cupi·ēns fū·gisse Le·ōnem
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Cornibus· adver·sīs et· proelia· fronte ge·rēbat;
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Nōn tua· frōns hor·renda mi·hī, nōn,· improbe,· cornū.
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Bellua· sī lon·gē, quam· tū plūs· fortis, a·besset,
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IMAGE. Here's an illustration for the fable (image source) by Milo Winter:
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What follows is an unmarked version of the prose rendering to faciliate word searches: Cives generosi, fortibus afflictis parcite! Turpe nocere fuit quos Fortuna premit. Bos celeri passu Leonem fugisse cupiens Hirco obvius est; Hircus via constitit; fronte et cornibus adversis proelia gerebat; cui Bos fugitivus rapidis verbis ait: "Improbe! Tua frons non mihi horrenda, tuum cornu non horrendum. Iste Leo, qui me sequitur, solus territat. Si bellua, plus fortis quam tu, longe abesset, mox humus sanguine vestro sparsa fuisset."