Is this kind of redundancy acceptable in both speech and writing, formal and informal ? Would the following sentences have their meaning changed if we omitted "personal" or "personally" ? Would they lose anything at all ?
- She is a personal friend of mine.
- It's my personal opinion....
- Personally, I would advise you...
- The manager said he will examine the matter personally.
- Personally, I don't care whether...
- I have a personal interest in the matter.
Generally, the word personal is used in these scenarios to indicate (or just emphasize) that the matter is, in fact, personal (from themselves without any other context to affect it). Let's take a look at your example sentences.
She is a personal friend of mine.
Without the "personal" there, there's no telling exactly how they're friends. A friend from work? A friend from school? Calling the friend a personal friend implies a somewhat less superficial relationship.
It's my personal opinion...
A person can have multiple opinions on a matter. For example, a climate scientist's professional opinion on whether global warning is an anthropogenic phenomenon would probably be that the evidence points towards it being so, while personally they may think it's just the perpetuation of natural climate cycles.
And as some others have pointed out, a public figure might prefix her opinion with "personal" when talking publicly in order to separate her own opinion from the opinion of her company or organization.
Personally, I would advise you...
A lawyer might give his friend who isn't a client some off-the-record advice on what will happen should they take a lawsuit or proceeding. A police officer might give a person he's talking to some unofficial guidance as to how to deal with a charge he's filing.
The manager said he will examine the matter personally.
If the manager were not examining the matter personally, he might examine it via one of his subordinates who would give him a report of the matter.
Personally, I don't care whether...
Again, a person may be forced to assume a particular impersonal opinion by virtue of their occupation. A traffic officer might not personally care that somebody's driving 20 km/h above the speed limit on a highway when everybody else is 15 over, but professionally he could never say that.
I have a personal interest in the matter.
If you advocate against pirating a game developer's games because you have stock investments in their company and don't want to see your investment lost, that's a business interest. If you advocate against pirating those games just because you think piracy is wrong and people shouldn't be stealing, that's a moral interest. But if you advocate against pirating those games because you like that developer's games and want to continue to have more games from that developer to play, that's a personal interest.
So yes, the word personal is indeed useful in these contexts, and not completely redundant either.
Personal is being used in at least three non-redundant ways in these examples
To distinguish a personal opinion from another opinion, for example a professional opinion, given by a professional person. It's my personal opinion....
As emphasis that the opinion is mine, and may differ from others. Personally, I would advise you...
To express a connection with the matter I have a personal interest in the matter.
The manager will examine the matter personally, rather than assign it to a subordinate.
The only case that appears redundant is She is a personal friend of mine.
Consider a person whose job it is to be the public face of an organization. Naturally, he has opinions of his own -- i.e., his personal opinions. However, because of his position as an official spokesman for his employer, whenever he makes a pronouncement, especially among strangers, he must make it clear whether he is speaking for his employer or for himself. In the latter case, he would use the "personally" formulation.
One point that seems to be missing in the other answers is that in some of these examples, the function of the word “personal” or “personally” seems to be connotative. For example, opinions are arguably always personal. Taking a (too) literal view of the meaning of the word, it would therefore appear that “personal opinion” is a redundant phrase.
But at the same time, the adjective does provide some color or nuances that should be readily perceived by most English speakers. In this case, beside the point others made about the distinction between speaking in a professional capacity or not, it might be a way to implicitly stress the validity of other opinions regarding the issue at hand.
Similarly, “I will examine the matter personally” shows a particular concern or sympathy for the other party or might be a way to express respect (“I'll do it personally because you're important”). You can only ever pretend you looked into something if you did it personally but just saying “I will look at it” sounds more distant or even slightly dismissive. (“I will examine the matter” also sounds a bit odd to me, so “I will examine the matter personally” could perhaps be interpreted as a conventional expression).
In speaking, the addition of 'personal' to 'my opinion' is a tactic of discourse. You might say 'my personal' opinion to poke an interlocutor who is not taking responsibility for her own opinions, but is rather claiming to spout universal truth. Or, you might say it rather pompously in mock modesty, to emphasize that the people listening to you are obliged to respect your point of view, because you are in authority.
The bullets in the question range across several different usages; some are variations on this, others convey other nuances. Perhaps others will fill in other aspects.
This word is often used purely as a "filler", but sometimes is used as a way to show emphasis to distinguish the person's views from the organisation they work for, or from any other affiliation they may be perceived to have.
However, this usage may also sometimes be used merely out of politeness, especially in British English. In British English it is common to put a view across in a manner that is tentative or even non-committal, in order to appear less forceful, and less aggressive, especially in formal or polite contexts.
It is redundant if the assumption about the personal statement is obvious, like when two girls figthing and one would say "(Personally, )I don't care whether you like me or not". However it gives an emotional flavour to the sentence and emphasize that I really don't care...
Your question highlights a specific example that may use personal unnecessarily or incorrectly - then follows it with a general question. There are some uses of personal that are incorrect, superfluous or ridiculous, as your question shows.
A person can hold opinions they form for themselves (rare) or that they get from their community (common). When people say they are expressing their personal opinion, they are almost certainly unaware that it isn't true - they are using a phrase they heard to qualify an opinion they heard - without analyzing either. They could correctly say: "... my opinion ...". My personal opinion should be reserved for those opinions earned not copied.
Perhaps the question should qualify the example with a suitable context.
