What are the best monolingual dictionaries of each language?

[verbling]

I only know of Spanish

Diccionario Real Academia Española.
Diccionario Maria Molliner.

I sometimes think that there are words in dictionaries that do not have much usability in real life street.

Do you know any?

[tomgosse]

For French, I use Le Petit Larousse.

[ilmari]

For Japanese, Kōjien 広辞苑 and Daijirin 大辞林. Super Daijirin スーパー大辞林 is the standard dictionary on Mac computers, which is a nice present.

[aokoye]

I sometimes think that there are words in dictionaries that do not have much usability in real life street.

For German I use Duden. In terms of words that you can't use much, you'll find that in any monolingual dictionary that is aimed at adults (as opposed to children). For example, the Paperback Oxford English Dictionary has over 120,000 definitions. That's actually a drop in the bucket compared to the Compact OED which has 500,000 words and phrases (some of which are obsolete and have been for hundreds of years).

I actually don't see any problem with a dictionary (for an adult) having words that you wouldn't often use in everyday speech because it is very very rare for people to learn words from a dictionary by going through every word and attempting to commit it to memory.

[YtownPolyglot]

To put the number of words in a dictionary in some sort of perspective, please let me refer to a test I found on social media that suggests that it would measure a person's vocabulary. I'm a university graduate with a master's degree in English, and I supposedly know just fewer than 30,000 words. Of course, there will be words in the dictionary I don't know. More often than not (I hope), these will be technical or specialized words.

I would rather have a dictionary that includes more words than I need than fewer words than I need.

[Sizen]

For French, I'm a big fan of Antidote. It's sometimes lacking in the modern slang department, but what it lacks in scope, it more than makes up in depth: thorough definitions often containing multiple entries, synonyms, antonyms, collocations, IPA transcriptions for Quebec and France (even for individual verb conjugations), and more.

As for Japanese, I'm personally a fan of Daijisen 大辞泉, but have also used Daijirin 大辞林 in the past. My favourite thesaurus is Weblio. It handles both individual words and expressions at the same time and also offers synonyms for different nuances in meaning.

For Catalan, there's the Diccionari de la llengua catalana which serves its purpose quite well.

[Hork]

Best German monolingual dictionary for learners is six-volume Wörterbuch der deutschen Gegenwartssprache published in the 70ies. It has many usage examples probably more than any Duden. It's online at http://retro.dwds.de/

[DangerDave2010]

For Brasilian Protuguese, I'd recommend the Aurélio Dictionary. But beware, useless words outnumber useful words by a factor of twenty to one.

[tiia]

For Finnish: Kielitoimiston sanakirja It also includes declination and conjugation to some extent. There's a printed version (3 books) as well, but that is quite expensive.

For German I'd also use Duden. Until the German orthography reform of 1996 it was the only official reference on how to write a word. I think the online version is made quite nicely as it includes declination, conjugation and synonyms. In some cases I used it as provement, that a certain word is only regionally in use, although not all regional expressions are marked as such.

But well, when it comes to technical words most dictionaries are not suffcient anymore. (Or am I just studying too specialized stuff?)

[Soffía]

In Icelandic I really like this one: http://www.forlagid.is/?p=569567

Don't own it yet, but someday...