1. Speaker 1 will make a speech supporting watching TV.

2. Speaker 1 will make a speech supporting the advantages of watching TV.

3. Speaker 2 will make a speech dissupporting watching TV.

4. Speaker 2 will make a speech supporting the disadvantages of watching TV.

(Are they grammatical? What useful terms can we use instead?)

1. OK

2. OK
3. No
4. OK

For 3 --
Speaker 2 will make a speech about the disadvantages of watching TV.
OR
Speaker 2 will speak against watching TV.

1. The sentence "Speaker 1 will make a speech supporting watching TV" is grammatically correct. However, a better way to phrase it using more specific terminology would be, "Speaker 1 will deliver a speech advocating for the merits of watching TV."

2. The sentence "Speaker 1 will make a speech supporting the advantages of watching TV" is also grammatically correct. Nevertheless, it could be enhanced by using more precise language like, "Speaker 1 will present a speech highlighting the positive aspects of watching TV."

3. The sentence "Speaker 2 will make a speech dissupporting watching TV" is not grammatically correct. It would be better to say, "Speaker 2 will give a speech opposing the act of watching TV."

4. The sentence "Speaker 2 will make a speech supporting the disadvantages of watching TV" is grammatically correct. However, it would be clearer to say, "Speaker 2 will deliver a speech outlining the drawbacks of watching TV."