Three key characteristics of Hebrew poetry, which forms much of the prophetic writing, are terseness, parallelism, and use of figures of speech (see here).
Hebrew poetry is very concise and compact, using few words in short lines. There are few conjunctions (‘and’, ‘but’, etc.), though translations into modern languages often add them to help clarity.
e.g. [Like] a gold ring in a pig’s snout
[is] a beautiful woman who shows no discretion. (Proverbs 11:22)
Words are often dropped out of the second of a pair of lines, leaving the reader to infer them. This is called ellipsis (the verb is elide).
Example 1 – Amos 4:4
Bring your sacrifices every morning;
[bring] your tithes every three years.
Example 2 – Isaiah 34:13
Thorns will overrun her citadels,
nettles and brambles [will overrun] her strongholds.
Most, but not all, Hebrew poetry makes uses of parallelism. Lines (cola; singular: colon) are usually in pairs, sometimes in triples or more.
The second line (and any subsequent line) repeats the idea in the first line, developing it in some way, often subtly.
Example 1 – Amos 1:2
A They sell the innocent for silver,
B and the needy for a pair of sandals.
Example 2 – Amos 2:14–16
A The swift will not escape,
B the strong will not muster their strength,
C and the warrior will not save his life.
D The archer will not stand his ground,
E the fleet-footed soldier will not get away,
F and the horseman will not save his life.
G Even the bravest warriors will flee naked on that day.
This is a form of synonymous parallelism, but the order of elements in the lines is reversed.
Example 1 – Isaiah 30:17
A thousand will flee at the threat of one;
at the threat of five you will all flee away.
Example 2 – Isaiah 11:13
Ephraim will not be jealous of Judah,
nor Judah hostile toward Ephraim.
Sometime the second line contrasts the first.
Example 1 – Amos 5:8 (line C contrasts line B)
A He who made the Pleiades and Orion,
B who turns midnight into dawn
C and darkens day into night, . . .
Example 2 – Amos 5:11 (lines B and D contrast lines A and C)
A . . . though you have built stone mansions,
B you will not live in them;
C though you have planted lush vineyards,
D you will not drink their wine.