会話は日常会話ができること。審査官の質問にスムーズに答える程度必要です。
ひらがな，カタカナは全て，漢字は小学２年生程度の理解力が必要です。日本人が小学２年生までに習う漢字の数は１６０文字です。
The applicant must be able to carry on a daily conversation. The applicant should be able to answer the examiner's questions smoothly.
The applicant must be able to understand all hiragana and katakana characters, and second grade kanji characters. The number of kanji learned by Japanese students in the second grade of elementary school is 160.

日本で生まれて国籍がもらえる特別なケースは，父母がともにわからないとき，又は国籍がないときだけです。通常日本国籍が取得できる場合は，父または母が日本国民であるときです。
The only special case in which a person born in Japan can receive nationality is when both parents are unknown or do not have nationality.
Normally, Japanese nationality can be acquired when the father or mother is a Japanese citizen.

はい，子の出生の日から３か月以内に国籍留保の届出をしないと日本国籍を喪失します。
Yes, Japanese nationality will be lost unless notification of nationality reservation is made within three months from the date of birth of the child.

いいえ，国籍の選択は義務付けられていますが，「日本国籍を失う」との規定はありません。

法務大臣が期限内に国籍選択をしない者に対して催告をしていた時期がありました。このときは催告から１か月以内に選択しなければ日本国籍を喪失していましたが，今は催告をしない取り扱いとなっています。また，外国の国籍離脱も強制ではなく罰則はありません。しかし，国籍離脱をするよう努める必要があります。
No, it is obligatory to choose a nationality, but there is no provision to "lose Japanese nationality".
There was a time when the Minister of Justice issued notices to those who did not choose their nationality within the time limit. At that time, if you did not choose within one month from the notification, you would lose your Japanese nationality, but now it is handled as not to be notified. In addition, renunciation of foreign nationality is not compulsory and there are no penalties. However, you should try to renounce your nationality.

いいえ，原則は５年以上住んでいる必要がありますが，次のような例外があります。

１．日本国民であった者（現在は外国籍となっている）の子は３年以上住所または居所があること

２．日本で生まれた者，または父または母が日本で生まれた者であり３年以上住所または居所があること

３．１０年以上日本に居所があるもの

４．日本人の配偶者は，婚姻前から引き続き３年以上日本に住んでいること。

５．外国で婚姻し，生活していた日本人の配偶者は，婚姻から３年，日本に１年以上住んでいること。

６．日本人の養子で養子縁組のときに未成年だったものは１年以上生活していること。

７．日本の国籍を失った日本人は日本に住んでいたらいつでもいい。（帰化した者を除く。）

 
No, as a general rule, you must have lived there for at least five years, but there are exceptions such as the following.
1. A child of a former Japanese citizen (now a foreign national) must have a domicile or residence for at least 3 years.
2. Those who were born in Japan, or those whose father or mother was born in Japan and who have had a domicile or residence for at least 3 years.
3.Those who have domicile in Japan for more than 10 years
4. Japanese spouse must have lived in Japan for at least 3 years continuously before marriage.
5. A Japanese spouse who has been married and lived in a foreign country must have lived in Japan for at least 3 years since the marriage and for at least 1 year.
6. A child adopted by a Japanese national who was a minor at the time of adoption must have lived in the home for at least one year.
7. Japanese people who have lost their Japanese nationality can always live in Japan. (Excluding those who are naturalized.)

はい，申請自体は自分ですることになります。しかし，１８歳になるまでは親が日本人である場合を除いて親と一緒でなければ１人で申請はできません。

実親が日本人であれば年齢に関係なく申請できます。このケースは，親だけが先に帰化した場合や，子供だけが外国で生まれて外国籍を取得して国籍留保の届出をしていなかった場合などが考えられます。
Yes, you will have to apply yourself. However, until the age of 18, unless the parents are Japanese, you cannot apply alone unless you are with your parents.
If your biological parents are Japanese, you can apply regardless of age.
In this case, it is assumed that only the parents were naturalized first, or that only the child was born in a foreign country and acquired foreign nationality and did not submit a notification of nationality reservation.