I. In the following sentences, I know that I should repeat "they", "they", "she", "he" and "it" instead of using "the <noun>" in the second part. But can I use 'the <noun>' if I introduce something using the verb "be" then talk about it with the second sentence directly following the first, not later on, and can the hearer understand that "the <noun>" mean "the noun I called it earlier"?
1 This is a letter. The letter is written in spanish.
(Does "The letter" mean "the letter I called it earlier"?)
2 It is a box. The box is red. I will open the box and …
(Does "The box" mean "the box I called it earlier"?)
3 That is a thief. The thief is tied to a post by a rope.
(Does "The thief" mean "the thief I called they earlier"?)
4 They are doctors but the doctors are not kind.
(Does "The doctors" mean "the doctors I called they earlier"?)
5 They are slaves, and the slaves are mine.
(Does "The slaves" mean "the slaves I called they earlier"?)
6 She is a slave, and the slave is mine.
(Does "The slave" mean "the slave I called they earlier"?)
7 He is a doctor but the doctor is not kind.
(Does "The doctor" mean "the doctor I called they earlier"?)
II. And when I use the other verbs, not the verb "be", so are they grammatically correct and natural?
8 I got a present. The present is a cat. I will give John the cat.
9 I bought a ball yesterday. The ball is red. When I kicked the ball, the ball flew over the fence.
10 She is biting an apple. The apple seems very rigid.
Thank you for your help!