"Mi madre siempre será joven."
Translation:My mother will always be young.
FINALLY someone said what the heck SER actually is. Almost no one will answer that!
One easy way to remember this is by remembering that "qué será, será" means "what will be, will be".
why is bad the phrase "My mother will be always young", if Always, adverb of frequency, it places behind verb to be
That word order isn't one that a native English speaker would ever use. The "be" needs to go after the "always". I cannot even think of an instance when it would be possible to reverse it.
I will always be yours
He will always be late
The door has always been brown
However, you can put "to be" in front of "always" in the present tense, and also in the past tense: She is/was always late. He is/was always with her. The door is/was always broken. They are/were always boring.
I have no idea why it is that way, maybe a grammar nut can explain it to us.
Another word order issue, if you are interested: "why is bad the phrase" - that should be "why is the/this phrase bad", or, better: Why is this phrase incorrect? / What's wrong with this phrase?
'forever ' and always' are the same for native English speakers so why is forever wrong?