a question from an English textbook

Verb form and tense can be a bit intimidating so, its best to pay great attention.
The following link will break down verb form and tense information for you, perhaps that will assist.

http://www.cfcc.net/rmorris/verbform.html

The essential meaning does not change. Let me label the sentences for my confusing explanation. ;-)


a) I would come with you tomorrow if I hadn't already arranged to go to Paris.

b) I would come with you tomorrow if I weren't going to Paris.


A) Shows a focus on the fact that the plan to go to Paris predates the issue of what will happen tomorrow. It is a conditional phrase (would) that is in the past perfect tense.

PAST PERFECT:

All the tenses that are something "perfect" mean that they refer to a time frame before a certain time.

For example, present perfect refers to things before the present (which is why it is so often confused with the simple past tense), future perfect refers to anything before a time in the future.

We are dealing with past perfect here, let me make a timeline.


PAST <----(8AM )-----------------------------------------(5PM )------PRESENT (the time of conversation)---------------------------------->FUTURE

8:00AM You arrange to go to Paris

5:00 PM Your friend calls leaving a message that asks you to go with him tomorrow.

5:10PM You call back and say you can't go because you had already scheduled something before he called.


Past perfect is formed using had + past participle (e.g. had eaten).

B) This one talks about future intent and does not focus on when the intent was formed. "going to" is used for an action in the future that is determined prior to speaking but it is a fine distinction. "Were" is used because it is a hypothetical conditional (as opposed to a "real possibility" conditional).

An example of the hypothetical conditional is:

If I were you.

NOTE: in hypothetical situations "were" supercedes the regular conjugation.

So this sentence is saying pretty much the same thing as the first, that the person is going to Paris but if that were not the case they would have agreed to go with the 2nd person tomorrow.

I believe the second sentence is written in the conditional subjunctive mood.

(For the reasons Kraven mentioned.)

Gosh, thanks Craven! That one had been bugging me - my grammatical knowledge has deteriorated so badly from a poor and arid base that I was unable to explain anything about how they were different!

>A) Shows a focus on the fact that the plan to go to Paris predates the issue of what will happen tomorrow.

Do I understand you correctly -

In the A case this guy underlines that his decision has been taken before his friends' call. So he may sound like: "You are too late. If you had phoned before 5 AM, I wouldn't have arranged my trip to Paris. But now I have already done."

In the B the guy means that he will go to Paris anyway, it doesn't matter when the friend called. Probably the trip had been arranged very long ago or is too important to be canceled?