They are both happy. NOT They is both happy.
Corrected sentence: They are both happy.
The correct punctuation for that sentence would be: "They all sang 'Happy Birthday' before she cut the cake." This includes putting 'Happy Birthday' in quotation marks and ending the sentence with a period.
Yes, the sentence "you saw your uncle and aunt come out" is grammatically correct. It describes the action of seeing both your uncle and aunt exiting from a place.
Both depending on what your entire sentence is. Try writing the sentence with both and reading it aloud. Whichever one sounds better go with.
Yes, that sentence is grammatically correct. It is a complete sentence with a subject (your parents) and a verb (are gone).
The correct phrase is "he and I" because "he" and "I" are both subjects in the sentence. "Him" is an object pronoun and should not be used as a subject in this context.
Yes, you can say "congratulations to you", but most people usually just say "congratulations!" as an exclamation! :)
they are both happy. this is a subject verb agreemet.
Happy is the correct spelling.An example sentence is "Wendy was very happy with her new dress".
The sentence "Is Mary not Happy" is correct grammatically as a question. It defines Mary as the subject and not happy as the object. In the other sentence, though grammatically correct, it could be confusing. Not Mary could be construed as all people but Mary. I would use the first sentence, as it is clearest.
Grammer is correct or not for this sentence
both the sentence are correct
yes
Both everyone and everybody take a singular verb everybody is happy everyone is happy
There is nothing incorrect about saying 'it is what made her happy' providing that 'it' has been clearly defined previously in the sentence or paragraph.
You can start a sentence with such as, but it is not considered correct grammar to do so. Try rearranging your sentence so that such as is in the middle.
Both sentences are correct.
No, it is not grammatically correct. The correct form would be "Why would you worry instead of being happy?"