When you add 'the' to a noun you make it definite. So you could say 'I love dogs' - there is no 'the', so this means all dogs. If you add 'the' you are making it more concrete/definite - 'I don't like the dogs in this city.' Hope this helps Bob

the 是有指定的，就好像华语里的‘这个’， ‘那个’ ， the citizens =指定的一些居民；citizens = 居民们；btw , 'the' 过后的名词有单数也有复数的