Description:

The term 'sifre' is one of the general words for knowing and knowledge.

This is an area where English speakers have a lot of trouble. For one thing, Common has a similar divide to French, German and Spanish with two basic words for knowing, one for knowing information and the other for being familiar with a person or thing. The term 'sifre' is in the latter category, it means to be familiar with something. The other sense, knowing facts, is covered by the verb 'pex'. 

Noun:

As a noun, sifre refers to general knowledge or familiarity with a person, place, topic, skill, etc.

Verb:

As a verb, 'sifre' is a semitransitive noxaj verb that takes an absolutive subject which is the knower, and a dative indirect object, which is the thing known, be it a person, place, topic, skill, etc. It is a very versatile verb - these are just some of the possible uses:

• To indicate that you know a person - the person would be the object.
• Similarly a place or thing
• To know a skill. E,g., 'We nox sifre ija karate' - 'I know karate.'
• To speak a language, as an alternative to using 'zisse': 'We nox sifre ija Xafen.' - 'I speak Common'
• To know the way somewhere.
• As a highly euphemistic way to say that someone had sex with someone else, particularly in the past tense - 'A Toni nox sifre ija Katija' would be interpreted as 'Tony knows Katia', but 'A Toni noxa sifre ija Katija' comes across with a nudge and a wink as 'Tony has sex with Katia.'

Modifier:

As a modifier, 'sifres' means 'familiar'.