Hi Samantha,

First, I'll explain in general where can you find that Alif. That Alif is found in indefinite nouns and adjectives, when they are in the accusative case. In case you don't know the accusative case, you can think of the "object" in the English sentence.

e.g : قَرَأْتُ كِتابًا = I read a book

Note that in this sentence the word كِتابًا is the object of the verb قَرَأَ, and also indefinite, that's why we must add that Alif we spoke about earlier. (كِتابًا pronounced ki-taa-ban)

What you need to remember is that Alif is NOT a long vowel.

Another example : أَخَذَ الطَّالِبُ قَلَمًا = The student took a pen.

The same here, we have the word قَلَمًا indefinite, object of the verb أَخَذَ, that's why we must add the Alif.

Now, moving on to the sentences you asked about :

Let's take the sentence without كانَ or سَيَكُون :

الجَوُّ بارِدٌ  : This is a nominal sentence, and has two parts : Subject (= الجَوُّ)  and predicate (or information) (بارِدٌ)

When we introduce كانَ to the sentence, it changes the predicate (which is بارِد) and make it in the accusative case. That's why we have

كانَ الطَّقْسُ بارِدًا / سَيَكُونُ الطَّقْسُ بارِدًا

Remember, the Alif for the accusative case will be applied to all the predicate part of the sentence, even if we have adjectives and nouns

e.g : كانَ الرَّجلُ وَلَدًا صَغيرًا

Hi Samantha,

That's a very good question.

The first sentence is a simple subject-and-predicate sentence, where the predicate بارد is in the nominative case (مرفوع). In Arabic, the nominative case is indicated by a dhamma. Because بارد is indefinite, it has a tanween, i.e. double dhamma. The tanween gives the word an N sound at the end. Therefore, the word is spelled باردٌ and pronounced "baarid-un". As you might know, the vowels are commonly omitted in writing.

The second and third sentences are a bit different because of the word كان. When كان enters the sentence, the predicate of the sentence is called خبر كان (the predicate of كان) and is in the accusative case (منصوب). In Arabic, the accusative case is indicated by a fatHa. And again, because بارد is indefinite, it has a tanween, i.e. double fatHa. And to answer your question: When a word ends with a tanween fatHa, an alif is added for the tanween to be placed on it. (This is almost always the case. There are a few exceptions, the most common of which is when the word ends with ة.) Even when the vowels are not shown, the alif has to be present. Therefore, the word is spelled باردا and pronounced "baarid-an".

i can learing you arabic  

but i want for you learing enghlish  . [emoji][emoji]

Simply It's agrammatical changing . it's always like that when you add كان "or one of it's congugation and same like ظل بات أضحى etc ..." before the nominal sentensce 

and notice that it's not an Alif it's tanween with Fatha double fathas ً  leads to this Alif  and while you reading you're gonna pronunce it as Baredan with the tanween or you can say Bareda with astretched Alif .

formula:

makes the noun raf' and the khabar nasb

الله عليم // كان الله عليما