Depends on the question. For example, I can say "what do you think ...?" There the answer would be what you think. But if i say "how do you think ...?" The answer would be how you think.
That is the correct spelling of "thinking."
I have to think
Both are correct.
I think that it is always correct.
Rethink
"What do you think" is correct.
That is the correct spelling of "thinking."
I have to think
"He thinks" is correct. The verb "thinks" agrees with the singular subject "he."
Yes this is correct.
The sentence "I think I catch a cold" is not grammatically correct. It should be written as "I think I am catching a cold" to indicate the present progressive tense.
No, "will be had" is not a correct grammar. The correct grammar would be "will have."
Both are correct.
The correct spelling I think would be: "Tamagotchi,"
Both are correct, but "on foot" is more commonly used to indicate that someone is walking. "By foot" can also be used in some contexts to mean the same thing, but it is less common.
Yes, your question is correct.
I think that it is always correct.