551. Six have the accusative commonly in #-em#, sometimes in #-im#:

bipennem, -im, _two-edged axe_

clāvem, -im, _key_

messem, -im, _crop_

nāvem, -im, _ship_

sēmentem, -im, _planting_

strigilem, -im, _skin-scraper_

552. In the ablative, gender substantives have usually #-e#, and neuters

and adjectives have #-ī#: as,

#hoste#, _enemy_; #marī#, _sea_; #ācrī#, _sharp_, #brevī#, _short_,

#audācī#, _daring_.

553. (1.) Of gender substantives with the nominative in #-is#, a few

have only #-ī# in the ablative, and many have either #-ī# or #-e#.