[Alex80]

Hi everyone!
Can we make the answers to these questions shorter ?
1.How could the police avoid mistakes when using radar guns?
The police could avoid mistakes if the radar guns are used correctly and police officers are trained to use them properly.
Is it correct to say:
-If the radar guns are used correctly and police officers are trained to use them properly.(omitting the main clause) if that's correct, can we make the sentence more shorter? What changes are needed to start the answer with 'By' ?

2.what does the whole section of books about different careers in a library describe?
-It describes the various jobs and tells what skills or qualifications we need to do them. (Can we make the answer shorter by omitting 'it describes' but leavingthe verb 'tells'
Thanks in advance

[susan53]

First of all, a slight correction. You need to decide if you want to present this as an actual situation/possibility or a hypothetical one.
If an actual situation : How can the police avoid mistakes when using radar guns? The police can avoid mistakes if the radar guns are used correctly and police officers are trained to use them properly.
If it's hypothetical : How could the police avoid mistakes when using radar guns? The police could avoid mistakes if the radar guns were used correctly and police officers were trained to use them properly.
The order of information in the reply seems illogical however - the training would be the cause of them being used correctly, so it would make more sense just to say : The police could avoid mistakes if they were trained to use them correctly.

Now to your questions.

Example 1 : It depends if this occurs in spoken or written text.

1. If it's spoken,then the following would be normal:
A: How could the police avoid mistakes when using radar guns?
B: Well... if the guns were used correctly. That would mean more training so they know how to use them properly.

2. Alternatively, or if the context was an informal written context like a question/answer forum, (like this one!) then the information might be repeated but condensed:

Forum question: How could the police avoid mistakes when using radar guns?
Forum answer : Fewer mistakes would be made if the guns were used correctly, which would mean more training so they know how to use them properly.

3. If on the other hand it was in a formal written text - say a school essay, and the question was the essay topic and title, then I would expect longer sentences and repeated information:

(Title) How could the police avoid mistakes when using radar guns?

(Answer, paragraph 1) There are several ways that police could avoid mistakes when using radar guns. Firstly, they would need to ensure that all officers were fully trained in their use. This would involve ... etc
(Answer, paragraph 2) Another way to ensure fewer mistakes when using the guns would be to have standard procedures for their use. For example, ... etc.

In other words, how much information you need to repeat depends entirely on the context in which the language is being used.

Example 2 is different however as there is a need for "it" in order to make the sentences grammatical, and "tells" is also incorrect (you tell somebody something). You could however say : It describes the various jobs and what skills or qualifications we need to do them.

Again though, in formal written discourse such as an essay, you should never start a paragraph with a personal pronoun - so you'd need to repeat the topic :

Essay title : What do they books in the careers section of a library describe?
1st paragraph : Many libraries have a section devoted to careers. The books in this section describe different jobs, and the various skills and personal qualities which are needed to be successful in them.

I hope that helps.

[Alex80]

Thank you so much for this logical explanation, my friend.