Not quite. The word 'day' should be plural:
There are thirty-one days.
It is correct to say "such an exhausting day", and not 'Such an exhaustive day'.
Thirtyone point eight.
Both "which day" and "what day" are correct, but they are used in slightly different contexts. "Which day" is used when there is a specific set of options to choose from, such as "Which day of the week works best for you?" On the other hand, "what day" is more general and is used when there are no specific options provided, such as "What day is your birthday?" Both phrases are grammatically correct, but their usage depends on the situation.
It's correct to say that a person is good AT mathematics.
There is no such day! ******************************* The correct spelling is wednesday.
Treinta y uno
No, it is more correct to say, "What day is it today?"
No, it is not correct to say "one an." The correct phrase is "one and a half day" to refer to one full day and half of another day.
It is correct to say "such an exhausting day", and not 'Such an exhaustive day'.
31,000,000
Thirtyone point eight.
Thirtyone.
You would say "Have a euphoric day".
No.
yes it's absolutely correct
Usually 'tomorrow is (my/your/his/her/our/their) day off'.
It is correct, but you could also say:These daysNowadaysIn this day and age