Immediately

To answer the last bit, I think either form is valid here in Australia.

*checks*

Yep. It's to be an adverb that can also act as a coordinating conjunction. Hence:

"I left immediately after I got the address" -> 'immediately' is an adjunct modifying 'left' and 'after' is used as a conjunction.

"I left immediately I got the address" -> 'immediately' is used as a conjunction.

And there's the mechanics behind it. As far as reasons go, I'd imagine it has something to do with how they sound.

Spammy. In the below, I couldn't decide between 'It seems to be an...' and 'It's an...'. I noticed immediately after the comment was posted. I thought some clarification would be useful immediately I noticed the error.

I remember reading, in American novels more than a hundred years old, "directly" used in the same way. Probably the usage has just fallen out of currency here in the States.

It does sound a little odd, should you not be used to it. "Directly" does sit a little better than "immediately", though.

As an American, I find the provided example very odd-sounding. In fact, I can't think of any instances where using an adverb as a conjuction sounds normal to me. Can adverbs truly be used in that sense (in a grammatically correct universe)?

Actually, I just googled that question, and was reminded that words like "nevertheless" and "consequently" are adverbs and are used as conjunctions. However :) I think that those may belong to a special class of adverbs.

And on top of that, if you leave out an "after" in the example sentence, it's unclear. Did the speaker leave immediately "after", "before", or "as" he got the address?

The implication in the example sentence is that the two events are non-concurrent (ie, one happens, and then the other, with no delay between).

The ambiguity only seems to exist since you're so incredibly used to seeing a preposition there.

(Starting to suspect I know the identity of Persephone.)

It's ugly alright. I think it jars because it seems to be operating as an adverb rather than a conjunction, as Persephone points out, making it seem like there's a word missing. 'Immediately after' is comforting but it's a complete contradiction in terms.

My guess is this came into legitimacy by common usage so I'd therefore be wary of trying to find a grammatical rule to explain it... it's a grammatical abomination! :)

(to make it easy, I use this username for the WtC forums, the FateRPG mailing list, and planewalker.com; I also use active_apathy for LiveJournal, and various names for the Keep)

Immediately is perfectly valid as an adverb - 'I'll reply immediately', for example.

Of course, the irony of adding a redundant word in a language that changes due to laziness amuses me greatly.

I don't agree "immediately after" is a contradiction in terms or redundant. You can also say "immediately before". Taken out of context, the single word "immediately" doesn't mean instantly after something. All it means is that something is instantly taking place after OR before an event. If you don't specify "before" it would be interpreted as "after", but to actually clarify it by adding "after" is not odd or wrong, but perfectly logical.

To be perfectly technical about it, 'immediately' means 'with nothing between' - for example, you can be immediately involved in something.

If "I left immedately I got the address", then the sentence can be recast as "I got the address, and left without delay" with identical meaning.

Indeed, one of the meanings of the adjective 'immediate' is that which is next in order - similarly, the idea being expressed is that leaving is the very next event after getting the address.

You can actually use "immediately" in any direction in space or time, so you can have "immediately before," "immediately after," "immediately above," "immediately behind," etc. The sense is equivalent to "right next to."

By analogy, you can have specialized uses like "immediately inside the doorway" (right next to it on the inside, like where you might find a light switch), "immediately over the next hill" (just as you get to the other side), "immediately across the street from," or "following immediately upon his heels" (like what a dog does when walking with his master). You'll get to know these by experience.

Some constructions you cannot have include "immediately in," "immediately from," "immediately to," and so forth.

Just to clarify "immediately to"....

You can have a sentence such as "Jane went immediately to the kitchen to make coffee," or "Mike set immediately to work on the dirty dishes in the sink." But in those cases you don't have the phrase "immediately to" as I was discussing below.

In the first example, the "to" belongs to the prepositional phrase "to the kitchen." In the second, the "to" belongs to the infinitive (basic verb form) "to work."

Persephone: But "with nothing between" doesn't say before or after or whatever. That's up to the rest of the sentence to clarify.

Anonymous: The use of simple past in both clauses implies that both events have, in fact, completely occured.

Since (a) getting the address cannot have completely occured after departure, and (b) it's certain that the departure has in fact occured, it's fair to say that leaving comes after getting the address, even without the aid of a preposition.

Uhm yes that's exactly what I said (anonymous), that the rest of the sentence has to clarify the meaning. The word immediately, with the meaning "with nothing between", doesn't do it by itself. Thus, there is nothing strange with saying "immediately after".

This is a trend I often notice. It refers to the occasional "dropping" of a preposition, and it does occur more frequently in British English. For example, "I accepted the gifts given me" rather than "I accepted the gifts given to me". Or, in another instance, "I enjoy the pastries the prepares", rather than "I Enjoy the pastries that he prepares." I have to admit, "after" is a strange on to drop, but I readily see the logic.

And I must apoligise for my typos. The detract from my comment.

Sorry for that one. "The" should be "They".