Measurements aloud: kilometroj, komo and po

The SI prefixes

The prefixes work exactly as they do internationally, and only on units of measurement:

• La urbo estas dek kilometrojn for. - The town is ten kilometres away.

PMEG lists the full set, up to kveta- (ten to the thirtieth) and down to kvekto-. Several of the words are already official, such as kilometro and kilogramo, and PMEG says most such words can be treated as roots in their own right.

Two oddities. Hektaro, a hectare, and megomo, a megohm, are irregular, but the regular hektoaro and megaomo are also usable. And miriametro, ten thousand metres, became an official root although neither it nor its prefix is used any more.

Decimals: the comma read as komo

Esperanto writes a decimal comma, as most of Europe does, and reads it komo. The digits after it are read one at a time:

So 46,987 is never komo naŭcent okdek sep. A half can also be said as a fraction:

• naŭ mil kvarcent tri kaj duona kilometroj - 9403.5 kilometres
• ok kilogramoj kaj sescent gramoj - 8 kilograms 600 grams

Rates: po at the front

Po marks a rate, and it goes in front of the whole amount. The unit then takes en, por or a plain adverb:

Traditionally the amount after po stays in the plain form: po dudek dolaroj. Many speakers add the -n when the sentence calls for it, kostas po dek dolarojn, and PMEG accepts both. Po can sometimes be left out, often with ĉiu added:

• La pomoj kostas du dolarojn por ĉiu kilogramo. - The apples cost two dollars a kilogram.

The classic error copies English per and puts po before the unit. Zamenhof's own example of the right form is po 80 centimoj por (ĉiu) funto, eighty centimes a pound.

Sums aloud

Faras is the older verb for equals; estas and egalas al are commoner today.