The question is asking us if yesterday was Monday. This is a direct question, so we begin by answering yes or no. We will omit the subject in our answer, as it is clear what is being discussed. We arrive at this answer:
はい、月曜日でした。
はい、げつようびでした。

The question is asking us if yesterday was Monday. This is a direct question, so we begin by answering yes or no. We will omit the subject in our answer, as it is clear what is being discussed. We arrive at this answer:
はい、月曜日でした。
はい、げつようびでした。

‘きのう’ does have kanji associated with it, ‘昨日,’ but they are nearly as often used as the hiragana form.
The question is asking us if yesterday was the fifteenth day of the month. This is a direct question, so we begin by answering yes or no. To practice a different form, we will use the negative form. Because we are trying to say that yesterday among all the days was not the fifteenth, we will reiterate the subject, though we grammatically do not need to. We arrive at this sentence:
いいえ、昨日は十五日じゃなかったです。十三日でした。
いいえ、きのうは十五日じゃなかったです。十三日でした。

The question is asking us if yesterday was the fifteenth day of the month. This is a direct question, so we begin by answering yes or no. To practice a different form, we will use the negative form. Because we are trying to say that yesterday among all the days was not the fifteenth, we will reiterate the subject, though we grammatically do not need to. We arrive at this sentence:
いいえ、昨日は十五日じゃなかったです。十三日でした。
いいえ、きのうは十五日じゃなかったです。十三日でした。

There are two katakana words in Japanese that are derived from the English word ‘hamburger’: ‘ハンバーガー’ and ‘ハンバーグ.’ ‘ハンバーガー’ refers to the American-style sandwich that you would get at MacDonald’s or another fast-food chain; ‘ハンバーグ’ refers to a Japanese dish comprised of a hamburger patty made with sauteed onions and then served in a red wine reduction sauce. Despite sounding similar, the dishes are very different, so be careful with your pronunciation.
The question is asking us if today’s breakfast was a meal of hamburger sandwiches. This is a direct question, so we begin by answering yes or no. Since hamburgers are not breakfast foods, we will answer in the negative. Because we are trying to say that breakfast among all the meals we may have had was not comprised of hamburgers, we will reiterate the subject, though grammatically we do not need to. We arrive at this sentence:
いいえ、今日の朝ご飯はハンバーガーじゃなかったです。
いいえ、きょうのあさごはんはハンバーガーじゃなかったです。

The question is asking us if today’s breakfast was a meal of hamburger sandwiches. This is a direct question, so we begin by answering yes or no. Since hamburgers are not breakfast foods, we will answer in the negative. Because we are trying to say that breakfast among all the meals we may have had was not comprised of hamburgers, we will reiterate the subject, though grammatically we do not need to. We arrive at this sentence:
いいえ、今日の朝ご飯はハンバーガーじゃなかったです。
いいえ、きょうのあさごはんはハンバーガーじゃなかったです。

The question is asking us if we were a good child during our childhood. This is a direct question, so we begin by answering yes or no. You will notice that the subject is omitted in the question itself, as it is clear that we are the one being asked the question. Because of this, we do not need to insert a subject. The answer will include the word ‘child,’ so we do not need to reiterate the reference to our childhood itself. We arrive at this sentence:
はい、いい子供でした。
はい、いいこどもでした。

The question is asking us if we were a good child during our childhood. This is a direct question, so we begin by answering yes or no. You will notice that the subject is omitted in the question itself, as it is clear that we are the one being asked the question. Because of this, we do not need to insert a subject. The answer will include the word ‘child,’ so we do not need to reiterate the reference to our childhood itself. We arrive at this sentence:
はい、いい子供でした。
はい、いいこどもでした。

The question is asking us if we were a good student during high school. This is a direct question, so we begin by answering yes or no. You will notice that the subject is omitted in the question itself, as it is clear that we are the one being asked the question. Because of this, we do not need to insert a subject. Though we do not need to reiterate that we were a good student during high school, we can use a slightly different word and say that we were a good high school student (‘高校生/こうこうせい’). We arrive at this sentence:
はい、いい高校生でした。
はい、いいこうこうせいでした。

The question is asking us if we were a good student during high school. This is a direct question, so we begin by answering yes or no. You will notice that the subject is omitted in the question itself, as it is clear that we are the one being asked the question. Because of this, we do not need to insert a subject. Though we do not need to reiterate that we were a good student during high school, we can use a slightly different word and say that we were a good high school student (‘高校生/こうこうせい’). We arrive at this sentence:
はい、いい高校生でした。
はい、いいこうこうせいでした。