What Are Impersonal Pronouns?
If we want to talk about people in general, can we say, 'You must be responsible toward the environment' or 'one must be responsible toward the environment?'
One vs. You
What Do They Have in Common?
'One' and 'you' are both impersonal pronouns, which means they can be used to refer to people in general, regardless of their gender.
But Are They Interchangeable?
If we want to give a short answer, we would say that either one of these pronouns is grammatical and correct. Both pronouns are what we call impersonal, or generic pronouns. But the only difference between the two is that one of them tends to be more formal than the other and you cannot use it in informal or spoken language. If you overuse it, you might sound arrogant.
We can use 'one' to refer to people in general. We can also use it to refer to ourselves. This function of 'one' now is considered very formal and old-fashioned.
It is much more usual to use 'you' for 'people in general' and 'I' when you want to refer to yourself.
Both these examples, sound haughty or way too formal and not acceptable in modern informal English.
'You', or to use a more grammatical term, 'generic you' is a more neutral and informal equivalent of 'one' as an impersonal pronoun.
When we use 'you' and not 'one' to refer to people we are referring to 'ourselves and everyone that is in our hypothetical situation'.
You should use the impersonal pronoun 'You' more often, unless you want to purposefully look down on other people and sound arrogant or unnecessarily formal.
Can We Use Impersonal 'One' as an Object?
Again, the short answer is yes. There's no rule against it. But it is recommended that you avoid using 'one' as an object because you might sound too formal or too unnatural.
'One' is the object of preposition in this example and as you might have noticed, it sounds unnatural and bizarre.
What about Gender Bias?
There might be another problem when you want to use 'one' as a generic pronoun. As you know, 'one' includes both males and females. So, you might hear sentences like:
But these types of sentences (with mixed pronouns) are no longer acceptable. Now the society is more sensitive about gender bias and mixing pronouns is not acceptable anymore. Throughout the sentence, you should use generic pronouns.