For practical discussion, verse spans can be classed as long, medium, and short. These are broad rhetorical groups rather than a rigid system requiring the same word count in every verse.
Examples of the longer manner occur in passages of al-Nisāʾ; medium-length passages can be considered in al-Aʿrāf and al-Anʿām; and many shorter verse patterns occur in al-Shuʿarāʾ and al-Dukhān. Individual passages may still vary within a surah.
Effect on meaning: length can allow detail and gradual development, a medium span can carry steady exposition, and brevity can heighten warning. None of these effects should be imposed mechanically on every occurrence.