Affixes III: -il-, -ajx-, -ar-, -er-, -ing-

-il- names the instrument that performs the root's action, so the root is nearly always a verb. tranĉi gives tranĉilo, ŝlosi gives ŝlosilo, skribi gives skribilo, veturi gives veturilo, and flugi gives flugilo, a wing, which shows that the tool need not be manufactured. The result is a noun in -o, and ilo also stands alone meaning tool.

The competition is with -ist- and -ej-: the same verb gives you the doer, the place and the implement, so kuiristo, kuirejo and kuirilo divide the kitchen neatly between them. Beware the ordinary roots that end the same way. facila, simila, trankvila and utila are adjectives with no suffix inside them.

-aĵ- makes a concrete thing out of whatever the root is. From verbs it gives the product or the object: manĝi gives manĝaĵo, food; trinki gives trinkaĵo, a drink; konstrui gives konstruaĵo, a building. From adjectives it gives a thing with that quality, so nova gives novaĵo, a piece of news. Always a noun in -o.

The pairing to learn is with -ec-. -aĵ- is the thing you can touch, -ec- the abstract quality, which is why bonaĵo is a good deed and boneco is goodness. -aĵ- also does the meat trick, turning an animal into what you eat: bovo gives bovaĵo, beef. aĵo alone simply means a thing.

-ar- gathers many of the root into one organised whole. arbo gives arbaro, a forest; vorto gives vortaro, a dictionary; homo gives homaro, humankind; ŝtupo gives ŝtuparo, a staircase; vagono gives vagonaro, a train. The result is a singular noun in -o, and that singular is the point.

Do not confuse it with the plural -j. arboj is several trees standing about; arbaro is a forest, a single thing with a shape of its own. Its opposite number is -er-, which cuts a mass down to one grain. aro also lives alone, meaning a group or flock, and takes da after it. Watch the false friends: jaro, maro, kara and paro hide no suffix.

-er- is the exact reverse of -ar-: it cuts a mass or a whole down to one of its smallest bits. mono gives monero, a coin; pano gives panero, a crumb; fajro gives fajrero, a spark; neĝo gives neĝero, a snowflake. Always a noun in -o.

The trap is that the fragment is the natural unit, not merely a small piece. A panero is a crumb, whereas a slice you cut yourself is a panpeco, so reach for -er- only when the thing genuinely comes in grains. Nothing in the top thousand words ends in -ero by suffix, and plenty end in it by accident: afero, letero, numero, papero, vespero and mistero are all single roots.

-ing- names the holder that one single object is slid into. kandelo gives kandelingo, a candlestick; glavo gives glavingo, a scabbard; fingro gives fingringo, a thimble; dento gives dentingo, the socket of a tooth. Always a noun in -o.

The distinction to nail is against -uj-. An -ingo takes one thing and takes it part of the way in, so the candle still shows; an -ujo takes many things and closes over them, which is why sweets go in a sukerujo and not a sukeringo. -ej- is a third neighbour, and it means a place rather than a container. ringo is a plain root, unrelated, and catches everyone once.