English grammar experts are invited to come in non experts are required .

The first sentence is something you regret doing. "If I had known this, I should have been there sooner"The truth is that you're late.

The second sentence is the possibility of speculation. The truth is that they're late, but you don't know why, guessing they might be lost.

First of all, affirm that the landlord's understanding is correct.

The first sentence is the subjunctive mood form in the if conditional sentence, so it is a fixed sentence form. That is, the conditional clause is the opposite or impossible of the present facts. In this sentence, it is "if I knew" but the truth is "you didn't know at that time".

So it's a fixed sentence in the subjunctive mood.,could doesn't have a special meaning here.,It's about the same as should.,I believe the landlord knows.。

The second sentence is to guess suppose, and could means "probably". My guess is that they may be lost.

The landlord uses machine translation.

Not only is there a problem with tenses, but also with English itself.

develop is juxtaposed with the previous provide, both as do in the should do usage, and their conjunctions are but also

Directed by the thought of lifelong educaton, on the other hand, is used as an insertion to modify the sentence that follows it, and the hallmark of this usage is that the insertion is separated by two commas. In fact, if you remove the insertion, you can clearly see the structure of the sentence.

It's okay for a sentence to have no conjunctions. Such as: I like you. There are no conjunctions. Both times are verbs and should be predicates.

a;The first question is how do you get to the airport to meet your grandmother. The answer is by, because there is a my, collocation question.

The second question is C, just a fixed collocation, the answer to the question; Similarly, the key to the door

1by my car

by+ way, what way, this is the way to go by car.

2on it.

Buying a book depends on your own needs and your own situation. Here are a few of my takes:

1. You don't need too much practice in grammar books. Grammar knowledge is acquired through a comprehensive and systematic study of grammar books word by word, and then through continuous reflection in daily reading practice, rather than by doing grammar problems. Remember: the highest level of learning grammar is to forget grammar!

2. The arrangement of grammar books should be innovative. In terms of arrangement and design, it is best to classify the sentence structure function, that is, to explain it according to "subject, predicate, object, definite, adverbial, and complement", which is more helpful for our understanding of the characteristics of English form and enhance our ability to analyze the structure of long sentences.

3. I think: The grammar of both Zhang Daozhen and Bo Bing is too detailed and cumbersome, which makes people feel dizzy and dizzy when they read it. Judging from what you have discussed, you should first go to the market and buy a high school English grammar book (basic grammar has been taught in high school, this is the core of English grammar, don't underestimate it!). There is basically no difference in the quality of grammar books at this level, as long as you remember to comply with the two principles discussed above. Once you've read through it word for word and made sure you understand it thoroughly and have no questions, it's time to move on to the next step. For this second step, I also recommend Zhang Zhenbang's "New English Grammar Course".

At the same time, I suggest that you buy another copy of the "English Difficult Problem Solving Dictionary" edited by Professor Zhao Zhencai of Harbin Institute of Technology.

good luck!

In my opinion, your thinking is incorrect, what is it to learn English? What is the English test? Now the fourth and sixth grades no longer take grammar as a big problem, what is the reason?

My English teacher told me that grammar is actually very simple, and there are only a few things in total, but the countless irregular things such as formulas and collocations in English are the most difficult to learn.

How do you need an "authoritative" grammar book? Are you afraid that other grammar books will make mistakes? There's nothing esoteric about grammar, so why bother unless you're a grammar student?

I think the key to learning English is to memorize, read, listen and speak more. So just reading grammar books has some benefits, but don't learn "dumb English".

Personally, I think that Zhang Daozhen and Bo Bing's grammar book is the most comprehensive and detailed. It is sold at every bookstore. The thin ice grammar book in my hand is from the Enlightened Press, and it is very thick. Therefore, you need to be patient to see. Reading grammar books is not a shortcut to learning English.

New English Grammar Course (Teacher's Book).

Zhang Daozhen's "New Practical English Grammar". The latest version... Foreign Research Society's...

There are a lot of examples of books and life scenes from the original English and American texts... And there are a lot of proverbs and slang... When you use it, you will know that this book is good ...

And it's not expensive... It's thicker... And it's very detailed...

And there are differences and contrasts between British English and American English...

I am a good patriotic baby!

If you are patriotic and patriotic, why do you have to learn English?

Whether should be used here

Both what and whether can lead the subject clause, what will act as some components in the sentence, such as the subject and so on, what is the most important is that you need to study hardThe whether-led subject clause usually has a choice, as in your sentence, whether we will go depends on the weather

I wish you progress in your studies and go to the next level!

If you don't understand, please ask in time, satisfied, o( o thank you.)

You're going to use whetherIn the words of what, your sentence is problematic.

The first sentence is correctly inserted (,but in many times,) table, and the second sentence separates the two sentences, and the two sentences are unrelated.