Note that the l of the article assimilates with these consonants:
ش س ر ز د ذ ت ث ن ل ظ ط ص ض
it means that if the word begins with some of these consonant, the l of 'al' becomes it.
Sun = shams شمس
a sun = shamsun شمسٌ
the sun = ash-shamsu (NOT al-shamsu.) الشمسُ
and as you can see, the look of the article doesn't change. only the pronounciation changes.
When you write "ash-shamsu" in arabic, you add shadda above the 'sh', and take the sukuun of l away.
Jonne- you mean when a word starts with one of those consonants, I take the letter ALIF + the first letter of the word I want to add the article (the)? Another thing... I have no idea about the words you gave us for exercises. Remember we do not have vocabulary yet. So please at least in the beginning add its transliteration and meaning.