What Your Use of I/Me/We/Us is Saying to Others
Personal pronouns (I, you, he, she, it, me, him, her, we, they, us, them) and their possessive equivalents (my, your, etc.) signal aspects of our attitudes towards ourselves, towards the person we are talking to and towards what or who we are talking about. These signals will evoke reactions, consciously or subconsciously, in our listener...
1ST PERSON SINGULAR (I/ME/MY/MINE)
When we use I/me/my/mine, we are focusing the conversation on ourselves. There are often good reasons to do this, but overdoing it will push people away.
ENGAGING CONVERSATION
Engaging conversationalists are genuinely interested in the person they are talking to, which means they ask the other person about themselves and their thoughts. Clearly this is inviting a 1st person response, but it's a two way street: just blithering on endlessly about yourself is disengaging and boorish. (That's enough about me, let's talk about me!)
We all like talking about ourselves and appreciate being given the opportunity to do so... Good conversationalists give the other person that opportunity, and if they are talking to a good communicator, will get it back. I/me/my/mine narratives will therefore be interspersed with you/your/yours-oriented questions (and active listening)...
PERSONAL RESPONSIBILITY
But self-reference is also a way of "owning" things, of taking personal responsibility and/or acknowledging one's individual role in something. I'm sorry, I misunderstood is owning a communication failure, while You weren't being clear! is blaming it on the other.
I can help you with that sounds like you are receiving personal attention. We can help you with that sounds as if you will have the attention of several people focused on your problem (see below).
"IN MY OPINION..."
I have frequently seen comments to the effect that one should never use In my opinion... or I think.... But as a blanket ban, this is very poor advice. Certainly, saying in my opinion when the whole discourse is clearly and necessarily your opinion is redundant and to be avoided. But these kinds of phrases can be used contrastively, and quite appropriately, to inject your own view into a discourse that is otherwise not just your point of view.
(Side note: be very wary of "never use this" type advice regarding language. Human communication is rich and complex. A word or phrase that is redundant or poorly chosen in one context can be perfect in another. Mechanical language advice that ignores context of usage is usually not worth much.)
1ST PERSON PLURAL (WE/US/OUR/OURS)
When we use we/us/our/ours (as I have been doing here), we identify ourselves as one member of a like-minded group.
IN-GROUP IDENTIFICATION
In-group membership is important. We derive our sense of self from a whole range of such identifications (friends, musical tastes, sports clubs, political parties, religions...). Reflecting this in our word-choice can be powerful and telling.
This doesn't concern us; we don't do things that way. The speaker is saying, "there are many people who agree with me on this", which obviously adds weight to the statement: i.e. "this is not just my opinion". The impact of We have decided to go ahead with this is quite different to I have decided to go ahead with this.
Addressing an audience with I excludes them. Addressing them with you excludes the speaker (yourself!). Using we identifies the speaker with the audience as part of a like-minded group, which – provided it is true – is a very good approach to capturing an audience.
But if the audience does not agree: if there is a known pre-existing relationship that makes such an in-group identification arguable, then addressing such an audience as we is likely to produce rejection. A beleaguered CEO addressing disgruntled employees who feel their voice is not being heard should be very careful in her use of we/us/our/ours...
AVOIDING RESPONSIBILITY
Group identification can be interpreted as avoiding responsibility: hiding in a crowd. We will have to let you go (i.e. I am firing you). When the statement is clearly personal, framing it with a plural pronoun looks weak and disingenuous (except if you're the Queen of England).
CONDESCENSION
Maladroit use of we/us/our/ours can easily be condescending: we can't afford any more mistakes, if said as a warning or admonishment to someone who is perceived as having made a mistake, carries the following implications:
I think there is a group of like-minded people to which you belong (but have clearly forgotten)
I am telling you what members of this group – and therefore what you yourself - think!
It is difficult not to perceive that as condescension...
INCLUSION/EXCLUSION AMBIGUITY
But we/us/our/ours also hides an interesting ambiguity in English: we're getting a raise might mean "Me [and them] and you", or it might mean "me and them (but not you)". Linguists call this distinction inclusive/exclusive (of the 2nd person: you). Some languages have different pronouns for these two cases, but most European languages don't.
This can create tension. If you make an offer to a group of people and your interlocutor says We'll have to discuss this further, what do they mean? Are you going to be included in the discussion or not? There is no way of telling, except by asking.
It is sometimes advisable to avoid we/us/our/ours if the in-group status of the listener is unclear. Say rather We'll have to discuss this further with you (inclusive), or I'll have to discuss this further with my colleagues (exclusive).
There's a lot more we could say about this. Leave a comment! What have I forgotten about I/me/my/mine or we/us/our/ours?