طوال اليوم means "all the day", or "all day long". كل يوم means "every day" The word كل is somewhat a word you can encounter among Semitic languages and though they differ from each other, actually the usage is similar. I'm explaining to you the usage in Arabic. If you are interesed, you can see such similar usage in Hebrew as well. The Hebrew word is כל. 1. When is used with an indefinite, singular, genitive noun, it expresses "every" or "each": كل يوم = every day, each day, and you can compare this with the Hebrew כל יום 2. When is used with a definite, singular, genitive noun, it expresses "the whole": كل اليوم = all the day, the whole day, and you can compare this with the Hebrew כל היום 3. When is used with a definite, plural, genitive noun, it expresses "all of the": كل الأيام = all of the days, all those days, and you can compare this with the Hebrew כל הימים

hello; [مرحبا] كل يوم(*) = [kulla yaw'm]= every day but it's recommended to use this one : في كل يوم [fee kulli yaw'men]. About using : you can use this (*) in the final of the sentence.Or in the first sentence, but you should use "comma" [,] example: ألعب كرة القدم في كل يوم في كل يوم، ألعب كرة القدم about this one : كل الأيام , my friend was explaining everything as well, now i'd like to add something important.the (*) use to mean that you repeat something every day. but the the second with the plural it's a simple and it doesn't mean the repetition yet. It's just using to inform or to make something stable [ something doesn't change] [means that all days the weather is clod "something doesn't change"] في كل الأيام، الطقس بارد [means that all days are wonderful in the summer "inform about something"] كل الأيام رائعة في فصل الصيف + So remember that as well, [كل الأيام] not for repetition! طوال اليوم (&)= [tiwaala l'yaw'm] = all[time of] day. in otherwise during all the time of this day you do something. it's also using for the repetition of something. + the difference between (*) and (&) : (*): you repeat something every day. (&): you repeat something in all the time of one day. to mean you repeat something all the time of all the days, you can use : طوال الأيام = [tiwaala l-ayaam] regards.

طوال اليوم means tomorrow to night. كل يوم means every day.

its easy طوال اليوم=all the days كل يوم= everyday