I need your comment on "future tense"

From "Advanced Grammar in Use, Chapetr 11"

We can use will or going to with little difference in meaning in the main clause of an if-sentence when we say that something is conditional on something else-it will happen if something else happens first:
1- If we go on like this, we'll/we're going to lose all our money.
2- You'll/You're going to knock that glass over if you're not more carefully.

However, we use will(or another auxiliary), not going to, when we describe a future event that follows another. Ofetn "if" has a meaning similar to "when" in this kind of sentene.
1-If you look carefully, you'll find writing scratched on the glass.
2-If you move to your left, you'll be able to the church.

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I don't like his explanation. I need your comment on this. Thanks!

Pastel

(I would tentatively suggest.)

MrP

1- If we go on like this, we'll/we're going to lose all our money.
2- You'll/You're going to knock that glass over if you're not more careful.

In the first two examples, the situation is 'now'; 'will'/'going to' carry a real sense of the immediate future, from the speaker's point of view. The first two examples are statements of what the speaker believes will happen.

1-If you look carefully, you'll find writing scratched on the glass.
2-If you move to your left, you'll be able to the church.

In the second two examples, the situation is 'whenever'; there is no sense of the immediate future, from the speaker's point of view. 'Will' in these examples is predictive. The second two examples are instructions politely couched in IF statements.

>>>>>>>> I like the idea of "whenever", but I wonder why it can't be applied to the first two examples.  "If you're not more careful,you'll knock that glass over", which also implies that when you are more careful, you won't knock that glass over. In other words, when you're careless, the glass will be knocked down. In that case, "whenever".

Do you understand my point?

I'm great, thank you. Typhoon "Ma-Sa" is approaching Taipei tonight, so we have a day off tomorrow. I'm going to cram GRE vocabulary and demander l'heure en francias. 

How are you, MrP?

Pastel    

Let me try to defuzzify my thought.

The first two sentences would occur only when the action in the main clause is an immediate possibility.

1. If we go on like this, we'll/we're going to lose all our money.

— You and your friend are playing poker with Dead Hand Joe, the meanest poker player in the West. You mutter this to your friend when DHJ takes a swig of 150% hooch. Losing all your money is a real possibility, because you're both playing so badly and Joe is playing so well. (Despite the hooch.)

In other words, the context of this sentence always has to be 'now'.

2. You'll/You're going to knock that glass over if you're not more careful.

— Later, in an attempt to emulate Joe's winning ways, your friend takes a swig of the hooch. It has an immediate and drastic effect. As he clumsily lays down his 2 aces, you mutter this sentence. Again, it's a real possibility: the sentence has no context that doesn't involve now. (I think.)

Next morning, penniless (or dollarless), you take a tour of the area. Luckily, you have a guide book. First, you visit an old Elizabethan mansion. (What's an old Elizabethan mansion doing, in the Wild West, I hear you ask? Well, according to the guide book, it was imported brick by brick from Gloucestershire, England, in the late 1920s.)

The mansion has some very old windows. The guide book takes you into a little secret chamber at the top of the house. The windows are small and cobwebby.

3. If you look carefully, you'll find writing scratched on the glass.

— says the guide book. In other words, the situation is 'whenever': whenever you are standing in that spot, if you look carefully, you'll find writing on the glass. (It's Sir Walter Raleigh's initials, as it happens.) No matter when you stand there, you'll always see the writing, if you do as the book says: 'look carefully'.

And this is always true of the sentence, no matter what context you find it in. It doesn't have to be a guide book: a friend can say it to you, when you visit his house; or a connoisseur may say it to you, when he shows you a valuable old wine glass. The difference between this sentence and ##1 and 2 is that they relate to a particular situation: but this sentence may be repeated, again and again: whenever someone picks up the valuable wine glass, the connoisseur may say, 'if you look carefully...'

Thus 'predictive'.

And the same is true of:

4. If you move to your left, you'll be able to (see) the church.

— Whenever someone stands in that spot, and then moves to the left, he'll be able to see the church. (Till they build a block of flats in front of it, of course.)

But I could be completely wrong.

MrP

...anyone for five-card stud?...