Naturalisation and citizenship in Switzerland

Obtaining Swiss citizenship can be a lengthy and expensive procedure. There are two procedures, depending on your personal situation:
- the simplified procedure. General requirements: being integrated in Switzerland, respecting Swiss law, no risk for internal or external safety of Switzerland. Further: one of the following has to apply to you: (1) having lived in Switzerland for at least 5 years, being married to a Swiss for at least 3 years, (2) a child (under 22) of Swiss parents that has lived in Switzerland for at least 5 years.
- The normal procedure. General requirements: having lived in Switzerland for at least 12 years. Requirements on being integrated in Switzerland, knowledge of language, and so on, are different from canton to canton.

The simplified procedure
Naturalisation is only on national level. Cantons and councils cannot set additional procedures or requirements. The procedure usually takes 12 to 18 months and will cost 750 Swiss Francs plus additional costs for documents, photocopies, and so on. The procedure mainly consists of filling out a 4-page form with relatively simple questions on the requirements for the simplified procedure. You will be invited to meet a naturalisation officer. In the meeting, the requirements are checked again. If you are applying for the simplified procedure because you're married to a Swiss,  (s)he will be invited to attend the meeting as well. More info at https://www.ch.ch/de/erleichterte-einbuergerung/

The normal procedure
As naturalisation will take place at national, cantonal and council level, there are no general rules on its length, costs, requirements and so on. Expect to pay at least 1,500 to 3,500 Swiss Francs. The procedure will take at least a year and a half.

Double citizenship
Swiss law puts no restrictions to double citizenship, but your own country may put such restrictions. Check before applying, as it may be very difficult or even impossible to get back your original nationality once you've lost it.

Advantages
The main advantage of Swiss citizenship is, that you are allowed to participate for all votings and referenda - and there are many of them here in Switzerland. A second advantage is, that you have the unlimited right to be and live in Switzerland.

Possible disadvantages
Before applying for Swiss citizenship, men should check, whether they have to turn up for military service when they have become Swiss.

Hi, I have 2 questions..

1. When applying for the simplified, does it require fluency of the language?
2. For the adopted non Swiss children, can they get citizenship even they don't live for long in Switzerland?

The simplified procedure requires, that you are "integrated in Switzerland". This includes that you can speak and understand the local language - I don't know exactly what conditions apply (how good you need to speak it).
Adoption: that's traditionally a complicated thing. I don't know the details about that. You best check the official law text (google on "SR 141.0 Bürgerrechtgesetz Schweiz" and you'll find the full law text) or ask locally, for instance at the "Migrationsamt" or at the city council.

Please note, that the laws on naturalisation will change in 2018. I have no detailled law text available (but you may find one if you look in the internet), but it is important that you check the details, and in particular: which law text applies if you apply for citizenship at a moment that the current law is valid, and will be granted citizenship at the moment that the new law has come into use.