Kaixo eta ongi etorri!
Hello and Welcome!
This is the Wikibooks open-source Basque language course. The Basque language is reputed to be one of the trickiest to learn. Unlike the tonal languages of Asia or Africa, or the Caucasian languages with their mammoth numbers of consonants and vowels, Basque is not a difficult language to pronounce. That is, if you speak English (presumably you speak some, if you are using this course), there are few sounds in Basque that will trip you up. Those that are unique to the language, at least compared to its neighbours or to English, are not overly difficult to acquire. That should at least give you a bit of courage in continuing with your study of the language!
So what is it about Basque that makes it so difficult? Well, for starters, Basque is a language isolate. That is, there are no proven relatives of Basque, in the way that Spanish and Italian or English and German or even Gaelic and Pashto are related. This complicates learning new words in Basque. If they are borrowings from Spanish or French (or English), then they are pretty easy to remember; if not, then they can be extremely difficult to learn en masse. Consider, as an example, some of the words related to the kitchen, which is called sukaldea in Basque: aizto is a knife; sardeska is a fork; koilara is a spoon; and labe is an oven. Not everything seems positively foreign; those who speak a Romance language will recognize baso for glass and plateru for plate. The trick, at first, is to take it slowly. Whereas you might expect to be able to assimilate 800 words or so in the first two or three months of learning Spanish, German or Russian, this is a rather high bar to set for yourself with Basque. Later on, acquiring vocabulary is made easier through a bit of analysis. Basque is called an agglutinative language, meaning it likes to use suffixes, prefixes and infixes, so new words are frequently formed by adding a common tag onto the end or the beginning or in the middle of a simpler word.
Speaking of suffixes, a second point of complication comes from the fact that Basque is synthetic, rather than analytic. In other words, Basque uses case endings to denote relationships between words, much like in the Slavic languages or German. The difference is that Basque has plenty more cases than Greek's puny four or Russian's measly six. Sometimes these are essentially postpositions, sort of like English's prepositions, but added to the end of a word: mendira to the mountain = mendi mountain + -ra to the. Other times, suffixes will denote concepts more difficult to translate directly into English. Unfortunately, the large number of suffixes makes it difficult to construct even simple sentences without tackling the issue head on, but taken slowly they can be learned fairly quickly.
Finally, verbs, which are the truly difficult part of the language. In general, Indo-European languages (i.e. most languages spoken in Europe, except Basque, Finnish, Hungarian, Estonian, Turkish and some small minority languages) change their verbs according to person (I, you, he/she, we, they); tense (present, past, future); and mood (indicative, subjunctive, optative, imperative). Sometimes different forms of conjugations are used if a verb is transitive (it can have a direct object) or intransitive (it can't). Basque does all of these things, and then some. For starters, unlike in Indo-European languages, Basque doesn't just change the end of the verb, it changes the beginning too. It also has a few more moods (ex. the potential) and, finally, Basque has a complex system of denoting subject, direct object and indirect object - all of which are crammed into the verb itself. That's the bad news. The good news is that only about 10 or 12 verbs actually conjugate in Basque - all the others go into one type of participle or another (past, present, future) and leave the conjugating to an auxiliary that is either izan to be or ukan to have. You need to learn all their forms to be able to read a book or an article, but not to have a basic conversation.
Clearly, Basque is not a language to learn for those who want something quick and easy. Basque is a complex idiom, and is beautiful because of its complexity. Study of the language is a great starting part for those interested in just how creative humans can be with respect to language.