A conjunction is a word that joins two words in a phrase, or two phrases, or even two sentences in a new sentence. I have occasionally shown use of a conjunction i "and" in examples, but now is the time to explain more. Croatian conjunctions are basically similar to adverbs.
Inclusion and Exclusion: i and ni
There are conjunctions that connect words and phrases quite freely, where both parts stay on equal footing, none of them has to be rearranged, etc. One example is before mentioned i "and". Another type of conjunctions introduce dependent sub-sentences, or 'clauses'; an example is da and dok "while".)
The simplest conjunction is i "and" (right, just one letter, single sound). It links two words, phrases, or sentences that are both on equal footing, in no opposition whatsoever, and used in a positive sense:
Ivan i Ana rade. "Ivan and Ana are working". (two nouns)
Ivan je žedän i gladän. "Ivan is thirsty and hungry". (two adjectives)
Ivan je jeo i pio. "Ivan was eating and drinking". (two participles)
Ivan jede i pije. "Ivan is eating and drinking". (two verbs)
Uredi su u prizemlju i na katu. "Offices are on the ground floor and on the first floor". (two phrases)
An i can be used before each part, making a stronger statement, similar to English "both ... and ...":
I Ivan i Ana rade. "Both Ivan and Ana are working". (two nouns)
Ivan je i žedän i gladän. "Ivan is both thirsty and hungry". (two adjectives)
Ivan je i jeo i pio. "Ivan was both eating and drinking". (two participles)
Ivan i jede i pije. "Ivan is both eating and drinking". (two verbs)
Uredi su i u prizemlju i na katu. "Offices are both on the ground floor and on the first floor". (two phrases)
Another set of conjunctions are ni and niti "neither/nor". They link two words, phrases, or sentences, but they mean "none of them". They are actually negations of i and ili, so the multiple-negation rule apply — if you use them, you have to negate verbs:
Ni Ivan ni Ana ne rade. "Neither Ivan nor Ana are working".
Ivan nije ni žedän ni gladän. "Ivan is neither thirsty nor hungry".
Word niti is just an emphasized version of ni, and is mostly used as a last word in chain of excluded options (ni... ni... niti) to emphasize that even the last option is excluded:
Uredi nisu ni u prizemlju niti na katu. "Offices are neither on the ground floor nor on the first floor".
However, if you want to really emphasize exclusion, you can use niti... niti... niti. While English "neither" and "nor" have strict rules of use, Croatian ni and niti are much more flexible!
Remember: with ni and niti verbs must be negated.
Single Inclusion and Exclusion
Conjunctions i and ni can be used before nouns, phrases, verbs, etc. to indicate 'inclusion' or 'exclusion', similar to English "too", "as well".
Croatian is here (as in many other constructs) more precise in English. For instance, check the following sentence:
"Ana will visit Rome too".
Depending on the context, it could mean that Ana will visit Rome in addition to some other places, or that Ana will go to Rome in addition to some other people going to Rome at the same time.
Croatian uses another strategy and simply places i before the noun or phrase which is 'in addition':
Ana će posjëtiti i Rim. (= in addition to other places)
I Ana će posjëtiti Rim. (= other people will go there too)
What or who is "other" must be already said, known or implied... The word i can be put before verb as well:
Ana će tamo i prespavati. "Ana will sleep there as well." (not just visit)
It's also possible to emphasize exclusion of a single item. Beware, you have to negate the verb as well, since you're telling what is not going to happen or what did not happen:
"Ana won't visit Rome too." (a bit ambiguous)
Ana neće posjëtiti ni Rim. (= and won't visit some other places)
Ni Ana neće posjëtiti Rim. (= other people won't visit it too)
Mutual Exclusion: ili
Another conjunction is ili "or". It links two words, phrases, or sentences in a way similar to i, but it means "only one of them", "not both":
Ivan ili Ana rade. "Ivan or Ana are working". (two nouns)
Ivan je žedän ili gladän. "Ivan is thirsty or hungry". (two adjectives)
Ivan je jeo ili pio. "Ivan was eating or drinking". (two participles)
Ivan jede ili pije. "Ivan is eating or drinking". (two verbs)
Uredi su u prizemlju ili na katu. "Offices are on the ground floor or on the first floor". (two phrases)
ili can be used before each part, making a stronger statement, similar to English "either ... or ...":
Ili Ivan ili Ana rade. "Either Ivan or Ana are working". (two nouns)
Ivan je ili žedän ili gladän. "Ivan is either thirsty or hungry". (two adjectives), etc.
With Three or More Items
With both conjunctions, more than one part can be joined. Note that a comma is not written before a conjunction. Also, with i, time order can be implied:
Ivan, Ana i Goran rade. "Ivan, Ana, and Goran are working".
Otišäo säm u trgovinu, kupio meso i skuhao ručak. "I went to a shop, bought meat, and cooked a lunch".
I Ivan i Ana i Goran rade. "All of them, Ivan, Ana, and Goran are working".
Ivan, Ana ili Goran rade. "Ivan, Ana, or Goran are working".
Ili Ivan ili Ana ili Goran rade. "Either Ivan, or Ana, or Goran are working".
Opposition: a and ali
With conjunctions a (again, just one letter, single sound) and ali we can join only two sentences, or two phrases or verbs into another one. The conjunction a means just a contrast, and ali an opposition. In many cases, English translates a as "and":
Ivan radi, a Ana spava. "Ivan is working, and Ana is sleeping."
Ivan radi, ali samo do podneva. "Ivan is working, but only until noon."
Ivan danas radi, ali sutra ne radi. "Ivan is working today, but tomorrow he's not working".
With a and ali we have to use a comma (,). Genitive case podneva is explained in detail in 53 Strange Nouns and Collectives.
Remember: i is used only when there's no contrast whatsoever.
Order of Words
Conjuctions i and a cannot fill the first position of the sentence — they 'don't count as words'! The word after them is the first word, and so on:
I gladän säm i sit. "I'm both hungry and fed."
Otišäo säm u trgovinu i kupio säm meso. (word order!)
Nisäm znao, a gledao säm televiziju. "I didn't know, and I was watching TV."
But we can join participles (not sentences) and say:
Otišäo säm u trgovinu i kupio meso. (joined participles, not sentences!)
But ali and ili (they are longer, have a li appended, the way to remember the fact) count and fill the first place:
Ili säm gladän, ili säm sit. "I'm either hungry or I'm fed."
Nisäm znao, ali säm gledao televiziju. "I didn't know, but I was watching TV."
Conjunctions pa and jer
Time sequence, or sometimes cause-and-effect can be constructed using the conjunction pa, and seldom used te (not to be confused with a demonstrative):
Otišäo säm u trgovinu, pa säm kupio meso. "I went to a shop, and then I bought meat."
Bila je gladna, pa je pojela ručäk. "She was hungry, so she has eaten (a) lunch."
A pa really starts another sub-sentence, therefore it's at the first position of the sentences, the placement rule is applied twice, there are two 'second places' within the compound sentence.
Similar to pa is the conjunction jer, linking sentences, explicitly stating a reason; the sentence staring with a jer is the reason:
Pojela je ručäk jer je bila gladna. "She has eaten (a) lunch because she was hungry."
It's really an subordinate clause, but of the simplest type.
Remember: i and a do not restart the counting of words, the word after them is the first word, but other conjunctions serve as first words.
Updated 2014-08-22 (v. 0.4)