Just as Celinese uses a wide range of suffixes as part of its derivational morphology, the language has many prefixes too that can help you take words you know and stretch them, by employing them differently. One thing to note is that some prefixes trigger internal mutation - the same consonants that change (p, t, c, th and f) at the beginning of words (e.g. pafair > mo b-pafair) change in the middle of words when a prefix is added in front of them. This is not an exhaustive list, but an introduction to some of the main Celinese prefixes.
Né-/an- : These are two of the most useful prefixes for building your vocabulary. They both are used to negate adjectives and even some verbs and nouns. Some examples with né: theilast (lucky) turns to néðeilast (unlucky, unfortunate); pontheg (certain) changes to nébontheg (uncertain, unsure); édithig (caring) to nédithig (uncaring, callous). When the stress falls on another syllable, né turns to nê - e.g. nêthí [neˈθi] (I don't know; I am unaware of).
Examples with an, which also mutates most words it modifies, are bereðand (respectful, humble) becomes ambereðand (rude, uncouth); alsiast (moneyed, rich) to analsiast (poor, impoverished), and celínír (speaker) becoming angelínír (mute, silent person). There are no set rules that determine which of the two negational prefixes to use; an- is more common in Perís, né- in Chlasc and Ioðinbêr, but none of these three major dialects use one form to the complete exclusion of the other. "Nêgelínír" and "ambontheg", whilst not the traditional dictionary forms, are perfectly understood and admittable words.
Chen(o)-: From the adjective chenog (bad), the prefix chen can be used in a similar manner as mis- is used in English, used to refer to anything done incorrectly or badly, but is rather more common. For those who adhere to the spelling reforms of 993, chen's provoking of internal mutation is reflected in the orthography, and it also becomes chem before b. Some examples: chengrefír (pulp fiction author), chenleiðír (poetaster - bad poet), chenlaiðoê (misgovernance, bad leadership), chengeðorí (mismanage).
ðwy-: from the word for two and sometimes written as dwy, ðwy- is used to translate English words prefixed with bi- or di- (meaning double or half); examples being ðwydraigyn (bicycle = two wheel), ðwygelínast (bilingual = two language having), and ðwyceilí (disect = two cut). It is also used for concepts that are not expressed with a prefix in English; an example being ðwyburí, fold, literally meaning two bend. Try-, hyð etc can be used for three, four and so on.
lo- : Lo- (from the word for to) is often used to express causation, though how lo- forms differ from the original infinitive can be complex. Gloðí (I compromise, as in I compromise to benefit the other person) becomes logloðí (I make the other person compromised; compromising them for my benefit.) Loloiðí, from loiðig (loud), makes "to make loud"; lorí (get on the floor) contrasts with lolorí (to make someone get on the floor.)
cé: Ce- (from the word for with, written cê when the stress is marked on another syllable) is one of the most commonly used Celinese prefixes and usually denotes mutuality. Taking an example from lo, whilst gloðí means that one party compromises for the other's benefit, cêgloðí means that both parties compromise. Cêgynolchír is a person from the same generation as you (with + descendant = those you descended with); cêgaithír is someone with whom you work (a colleague), cêloithí is to place something together (to link), and cêsyrí is to enjoy (literally with-like).
na: (from the word for in, sometimes written as no), usually creates compound words containing in. Ingredient is naðon (na + thon, in-food, i.e. things in food), songwriter is noleiðír (in-song person, i.e. someone who puts things in song), naloileg means unavoidable (literally translating to "in the stars adjective") and nadolí is to insert (from na + tolí, add). Na always provokes internal mutation.
doir: This prefix comes from the preposition for "from one side to another" and often has parallels with trans- or cross- in English. Examples of its use include doirgrefí (translate = cross-write); doirarileg (trans-Atlantic), doirbyrí (to cross), and doirwyðar (transport, lit. across door/port in Celinese.)