Can you help me answer some questions about using the word "The"?

Question

I. In the following sentences, I know that I should repeat "they", "they", "she", "he" and "it" instead of using "the " 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"? Ex:

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 them earlier"?)

4 They are doctors but the doctors are not kind. (Does "The doctors" mean "the doctors I called them earlier"?)

5 They are slaves, and the slaves are mine. (Does "The slaves" mean "the slaves I called them earlier"?)

6 She is a slave, and the slave is mine. (Does "The slave" mean "the slave I called them earlier"?)

7 He is a doctor but the doctor is not kind. (Does "The doctor" mean "the doctor I called them earlier"?)

II. And when I use the other verbs, not the verb "be", so are they grammatically correct and natural? Ex:

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.

Answer 1

Most of the examples do work, as the purpose of 'the' is solely to mark which nouns have been previously introduced. So these examples form good examples of one common method of triggering 'the'.

Some of the examples are more problematic.

• They are doctors but the doctors are not kind.
• He is a doctor but the doctor is not kind.
• They are slaves, and the slaves are mine.
• She is a slave, and the slave is mine.

Here the linking is weak or non-existent, primarily because we would normally choose a different approach:

They are doctors, but they are not kind.

Language has to have the ability to be spoken quickly, so choices are often made based habitually on the choice that take the least computation. As choices are so often habitual, the alternatives can be relatively crude or different in meaning when we do choose to use them:

They are doctors, but as doctors they are not kind.

They are doctors, but they, the doctors, are not kind.

Finally, the other sentences. I am not sure where you got this idea that articles are related to verbs, but they are not. In English the verb phrase grammar is independent of noun phrase grammar, so much so that some creoles use English verb grammar with the noun phrase grammar from a different language.