We can use nowadays, these days or today as adverbs meaning ‘at the present time, in comparison with the past’:
I don’t watch TV very much nowadays. There’s so much rubbish on. It’s not like it used to be.
Young people nowadays don’t respect their teachers any more.
Warning:
Take care to spell nowadays correctly: not ‘nowdays’.
These days is more informal:
These days you never see a young person give up their seat for an older person on the bus. That’s what I was taught to do when I was a kid.
Pop singers these days don’t seem to last more than a couple of months, then you never hear of them again.
Today is slightly more formal:
Apartments today are often designed for people with busy lifestyles.
We can use today, but not nowadays or these days, with the possessive ’s construction before a noun, or with of after a noun. This use is quite formal:
Today’s family structures are quite different from those of 100 years ago.
The youth of today have never known what life was like without computers.
Warning:
We don’t use nowadays, these days or today as adjectives:
Cars nowadays/these days/today are much more efficient and economical.
Not: The nowadays cars / The these days cars / The today’s cars …