Yes, I wrote the sentences incorrectly:

Thank you

He was seen to watch the TV
He is still dependent on ... but independent of....
I was so angry WITH him FOR behaving like that in front of everyone. (about behaving would be a mistake?)
The teacher was annoyed WITH me FOR forgetting to phone (about forgetting would be a mistake?)

He was seen watching TV.

All else is correct.

Yes, I agree with the sentences. But Writeteacher, is the first one grammatically wrong? I don't see how.

Yes, there are some errors in the sentences you provided. Here are the corrected versions:

1. He was seen watching the TV.
In this sentence, the incorrect use of "seen to watch" has been corrected to "seen watching." When describing an action that is already in progress, it is more appropriate to use the verb's base form (watch) instead of the infinitive form (to watch).

2. He is still dependent on... but independent of...
This sentence is incomplete and requires further information to complete the thought. After the phrase "dependent on," you would need to specify what he is dependent on. Similarly, after the phrase "independent of," you would need to mention what he is independent of. Once you provide the missing information, the sentence will be clearer.

3. I was so angry with him for behaving like that in front of everyone.
Regarding your question, "about behaving would be a mistake?" - No, the word "behaving" is used correctly in this sentence. It functions as a gerund, which is a verb form that acts as a noun. In this case, "behaving" serves as the object of the preposition "for." So, there is no mistake regarding the usage of "behaving."

4. The teacher was annoyed with me for forgetting to phone.
Addressing your question, "about forgetting would be a mistake?" - No, the word "forgetting" is used correctly here. Similar to the previous sentence, "forgetting" acts as a gerund that functions as the object of the preposition "for." Therefore, there is no mistake regarding the usage of "forgetting."