The sequence in which you edit should usually be: first change the body, then update the lead to summarize the body. Several editors might add or improve some information in the body of the article, and then another editor might update the lead once the new information has stabilized. Don't try to update the lead first, hoping to provide direction for future changes to the body. There are three reasons why editing the body first and then making the lead reflect it tends to lead to better articles.
First, it keeps the lead in sync with the body. The lead, being a summary of the article, promises that the body will deliver fuller treatment of each point. Generally, wiki pages are imperfect at all times, but they should be complete, useful articles at all times. They should not contain "under construction" sections or refer to features and information that editors hope they will contain in the future. It's much worse for the lead to promise information that the body does not deliver than for the body to deliver information that the lead does not promise.
Second, good ways to summarize material usually only become clear after that material has been written. If you add a new point to the lead before it's covered in the body, you only think you know what the body will eventually contain. When the material is actually covered in the body, and checked and improved, usually by multiple editors, then you know. (If having a rough, tentative summary helps you write the body, keep your own private s
First, it keeps the lead in sync with the body. The lead, being a summary of the article, promises that the body will deliver fuller treatment of each point. Generally, wiki pages are imperfect at all times, but they should be complete, useful articles at all times. They should not contain "under construction" sections or refer to features and information that editors hope they will contain in the future. It's much worse for the lead to promise information that the body does not deliver than for the body to deliver information that the lead does not promise.
Second, good ways to summarize material usually only become clear after that material has been written. If you add a new point to the lead before it's covered in the body, you only think you know what the body will eventually contain. When the material is actually covered in the body, and checked and improved, usually by multiple editors, then you know. (If having a rough, tentative summary helps you write the body, keep your own private summary, either on your computer or in your User space.)
Third, on contentious pages, people often get into edit wars over the lead because the lead is the most prominent part of the article. It's much harder to argue constructively over high-level statements when you don't share common understanding of the lower-level information that they summarize. Space is scarce in the lead, so people are tempted to cram too much into one sentence, or pile on lots of references, in order to fully state and prove their case—resulting in an unreadable lead. In the body, you have all the space you need to cover subtleties and to cover opposing ideas fairly and in depth, separately, one at a time. Once the opposing ideas have been shaken out and covered well in the body, editing the lead without warring often becomes much easier. Instead of arguing about what is true or what all the competing sources say, now you are just arguing over whether the lead fairly summarizes what's currently in the body.
It is fine to include foreign terms as extra information, but avoid writing articles that can only be understood if the reader understands the foreign terms. Such words are equivalent to jargon, which should be explained somehow. In the English-language Wikipedia, the English form does not always have to come first: sometimes the non-English word is better as the main text, with the English in parentheses or set off by commas after it, and sometimes not. For example, see Perestroika.