No, there are misspellings.
Teddy bear sales remained significantly constant over the whole period.
No, here is how it should sound: There was a significant increase in the population.
"How are you" is a correct sentence.
Yes, this sentence is correct.
Try significantly ... if that's the word you are looking for.
You are palpitating. This is a correct sentence.
A constant is a variable that does not change. The correct term is constant variable.
no it is not a correct sentence.
That sentence is grammatically correct.
No one answer this, please. It is from their homework, I assigned it to my own class last year. Person who did this: It is very wrong to cheat. You should try and complete your homework independently or with a text book. If you have questions, ask your teacher! That's the only way you will learn it! :) Actually, the sentence is wrong. The correct sentence is: The surface of Earth is in constant motion because of forces inside the planet. :D
no_____If the sentence is You do do that (meaning You are in the habit of doing that) the grammar is perfectly correct and the sentence 'does have correct grammar'.
With the exception of not capitalizing the 'y' at the start of the sentence, it is a correct sentence.
"You and him" is correct in a sentence such as, "I sent the tickets to you and him," versus a sentence such as, "You and he should send the tickets to me."