Dear teachers,
I would like to thank you all for your time and your useful comments, especially Soup and fivejedjon. I think that, as an English learner, I have learnt a lot from you.
However, there is something I am still not sure about, and I need to have your confirmation, so that I can make a rule for myself. I would like to express my point below. Please correct me if I am wrong.
1. In the pairs of sentences below, we imply the comparison or the similarity between two people or two things.
I like music. He likes music, too.
(Positive statement + positive statement ....too)
She isn’t happy. He isn’t, either.
(Negative statement + negative statement ....either)
2. In the sentence I originally posted, I notice that there is a difference in meaning. In this sentence we do talk about requirement or giving advice.
“Children should spend only a small part of their free time playing video games. They mustn’t forget to do other things, too.”
The sentences imply that there are two things the children must/should do:
Play less video game + do other things ... too
Positive statement + Positive statement ... too
Despite the fact that the form of the verbs in the pair may be affirmative or negative, we focus only on the idea.
Am I correct up to now? If yes, please tell me.
3. If all my theory I have presented is correct up to now, I would like to continue that I am not sure about Khosro’s explanation:
"Children mustn't forget to wash their hands before meal. They mustn't forget to brush their teeths, either."
Please forgive me, Khosro, but my opinion is that the verb forget has a negative meaning, and that not forget means remember so I think I can apply Soup’s opinion as follow:
Children should:
Wash their hands before meals + brush their teeth ...... too
Positive statement + Positive statement .. too
I would like to have your opinion. I wish you all good health and thank you again.