definite-articledemonstrativedeterminersword-choice
I understand that "the" and "that" are both used to refer to a specific subject or object. But are there general rules of thumb to explain when we should use "the" and when we should use "that"?
Examples:
Both of these sentences are grammatical, but when one should be used instead of the other?
The king and his followers visit many poor villages.
That king and his followers visit many poor villages.
The difference between the two based on the "Cambridge dictionary" article, is as follow (quote):
"We use "it", "this" and "that" to introduce further information about a topic already mentioned. However, the words have different uses.
We use "it" to continue to refer to the topic we are already writing or speaking about:
The heart is the central organ in our bodies. It is used to pump oxygen around the body through the bloodstream. (It refers back to The heart)
Warning: We don’t use "it" when we first give information about a topic, for example immediately after a chapter or section title in a text:
(b) Green application form
*This* must be signed by all applicants and returned by 30 November 2009.
Not: *It* must be signed …
We can use "this" to refer back to whole clauses and sentences and to previous parts of a text. "This" highlights the information referred to much more strongly than it. Writers often use "this" when a point or idea is to become an important part of the discussion that follows:
More and more people are discovering that Tai Chi is one of the most valuable forms of exercise. This has led to a big demand for classes. (This refers back to a whole sentence.)
Heavy rains and stormy conditions throughout the summer have led to severe shortages in strawberries and other soft fruits. This has led to price rises in many supermarkets and shops.
We use "that" in a similar way to this. However, when we use "that", we distance ourselves more from the topic or from aspects of the topic:
For many traditional football supporters, it is a problem that so many young girls and women attend football matches these days. That is a sexist attitude of course.
"That" is also used to refer to ideas associated with another person:
The chairman apologised for the poor performance of the company and promised a better future for investors. That was a promise many people felt he could not possibly keep."
(All of the above is from the Cambridge dictionary. I've just added some graphics such bold letters etc. in order to make it easy for reading and understanding.)
The above Cambridge article deals with the using of "it", "this" and "that", while writing or talking generally. But the original question is also about a case of pointing on an animal or a fruit for example and talking about it. So in that case should we say "*It is a nice animal" or "This is a nice animal"?
It seems that it depends on context. If we are around with the ability to point on the object, meaning that we see it, then we can use "this" or "that" depends on the distance. But if we don't see it at all, we use "it".
In all the examples you give, use "this" or "these".
While you would be understood if you used "that", the thing you are referring to is your idea, and so it remains psychologically close to you.
So in the first example, you introduce the idea of "sound waves". It is not the physical location that matters, but the idea. In each case it is "these sound waves that I am talking about" or "This interaction that I say is unsuccessful"
You could use "that" or "those" when you introduce a comparison
... these sound waves can be heard by the health provider. This is different from an ultrasound system, as those sound waves are too high to be heard.
Best Answer
At a very basic level, that is the verbal counterpart to pointing at something in order to focus another person's attention on it in particular, so that the person does not mistake something else similar to it for it, or so that the person understands that the one being pointed at is different from others which may seem similar to it.
If you win a stuffed animal at a carnival, for example, you might say to the carny "No, I want that one." and mean thereby that you want a specific one, perhaps the one next to the one the carny was reaching for.
The, in contrast to that, refers to a particular thing the speaker has in mind.The is not so overt; the does not direct the other person's attention towards something.