we'll now take a closer look at 'schon mal' (already again?), 'noch mal' (again) ...

now then(?), first of all and not even

let's have a look at 'schon mal'

'I have already read this book (once)'

this sentence actually means the same as 'I have read this book (once)'

but this combination of 'schon' and 'mal' simply sounds very natural

and especially in questions, one is more likely to say 'schon mal' than simply 'mal'

so: 'have you ever read this book?'

'have you ever been to Hamburg?'

'have you ever been skiing?'

'mal' is very often combined with other words in spoken language

'schon mal' has yet another meaning

'I'll prepare the salad now'

'then we won't have to do it tonight'

'schon mal' here expresses doing something earlier than necessary

because it's sensible or practical

we want to eat the salad tonight

but I'm preparing it now because it's practical

then we can eat it right away when we get home tonight

or, 'Can you put the suitcase in the car?

I'll be right there'

well, actually, we could put the suitcases in the car together right now

'but it's makes sense if you do it now'

then we'll save time

note that the two words, 'schon' and 'mal', are written separately

even native speakers often make the mistake of writing them as one word

and remember, 'schon mal' is colloquial

in a formal text, you would write 'schon einmal'