I'm not sure I understand why or how to tell the difference? Is it simply context that tells you which one is which?
It is a grammar choice based on the subject of the sentence. For example you would say: C'est moi, for "its me", but not "il est moi". Or for telling time you would say "il est deux heure, not c'est deux heure. One is grammatically correct, one is not depending on the context.
Yes, depending on the context. Actually it can mean "he is" and "she is" as well, if followed by a modified noun.
The "t" siund from c'est is carried over to the "un" sound when the following letter is a vowel. So it is pronounced like "C'es t-un gateau".
You only prounce the 't' in 'c'est' when the following word begins with a vowel.
So is it a mistake to say "Il est un gateau" or it's correct just sounds a bit strange?
That would be incorrect.... That would translate to - "he is a cake". Il is a subject. You could say "Il y a un gateau" meaning "there is a cake". Because "il y a" is a phrase in french meaning different things depending on the context
"There is a cake" = il y a un gâteau. The expression "il y a" may be used as "there is" or "there are".
gâteau · how gâteau is masculine gender is a lengthy historical dig.
Gastel, from Frankish *wastil is etymologically cognate to the English past tense verb to be, "was" and had IE meanings such as substance, eat, to be, exist.
· gâteau · From Middle French gasteau, from Old French gastel, from Frankish wastil, from Proto-Germanic wastilaz, from Proto-Indo-European *wes- (“to eat; consume”). Compare Old English wist (“food; provision; feast”). · · en.wiktionary.org/wiki/gâteau · · en.wiktionary.org/wiki/gastel#Old_French · ]
Are you meant to pronounce the T in c'est? Because the person reading the sentence seems to do that, but not the person reading the single word when I click it.
That would usually not be the case, but I believe that it could work - depending on context.
Since the word after c'est started with a vowel sound, a French speaker would carry the T from c'est over to the un. This is called a liaison. French speakers like to make their language sound nice. :)
Isn't "gâteau" the same as "pie" or "cookie"? Isn't "It's" the same as "It is"?