Nowadays people spend too many hours or too much time texting

[yi-ing]

Is this sentence grammatical?

Nowadays people spend too many hours / too much time texting, surfing the Internet, chatting online, and watching TV. This may have an adverse effect on their both social and personal behaviours.

 

[yi-ing]

Do the following make sense too?

This may have an adverse effect on both of their social and personal behaviours.

 

[andrewg927]

Yes it makes sense but the structure is a little awkward and I prefer "behavior".

 

[emsr2d2]

As Piscean said, it's "both their". You changed "their both" to "both of their".

 

[Rover_KE]

yi-ing, you incorrectly added 'of'.

(You're probably aware that BE behaviour = AE behavior.)

(Cross-posted)

 

[Tdol]

In the original sentence, I find too much time more natural than too many hours.

 

[andrewg927]

yi-ing, you incorrectly added 'of'.

(You're probably aware that BE behaviour = AE behavior.)

(Cross-posted)

Oh, I didn't realize that about the spelling. I just meant I prefer the non-plural form of the word.