Generate the answer for a given question. The question requires common knowledge of English. Make sure that the answer is in detail, long, consistent with the context, and requires general knowledge of English. To be less repetitive, please vary your language for each question. Give a proper explanation to answer, and if necessary, provide the definition of various terms. And conclude your answer if it's long. If you have used other resources (e.g., Merriam Webster's.) to answer the question, include citations in your answer. You don't need to paraphrase the context of your resources, but make sure that your answer is consistent and complete.

[EX Q]: I am looking for the term describing when your hair grows kind of in a circular direction (defined by the direction of your hair root). Many people have something like this on the back of their heads or even on their foreheads. I found the term hair crown on dict.cc but I feel like this is either not the correct term for it or it is not very widely used. There is a German article on human hair including a section about these things but I could not find the English equivalent. In German, these are called Haarwirbel meaning something like hair whirl.
[EX A]: You probably want to use hair whorl. You'll notice that it's virtually the same as the German term, except with the alternate spelling of whorl/whirl. In English, whirl is the verb form, whorl is the noun.

[EX Q]: A few days ago, a friend and I were discussing how every 'rule' of English spelling or pronunciation has an exception, and every exception has an exception as well. Then I brought up the rule of a ph cluster equaling an f sound (as in phonetic, elephant, morph, etc.) as a pronunciation rule that didn't have any exceptions I could think of. Is this a true hard-and-fast rule or does it have some exceptions as well? I'm not counting abbreviations such as pH scale.
[EX A]: The exceptions come in two categories: Greek words that were originally pronounced with an 'f' diphtheria, diphthong, ophthalmology, phthisis but have come to be pronounced with a 'p' by no process I understand. Compound words uphold, saphead, peephole that are just a word ending in 'p' run up against a word beginning with an 'h'. Neither of those really feel like exceptions: mispronunciations that have become accepted and two words being treated as one. Then there is aphelion. Arguably, that's a compound word and a mistake. By analogy with apogee and apastron, it should be apohelion: 'apo' ('from') + 'helion' ('sun'). Several people brought up 'Stephen', which is often pronounced like 'Steven'. Eh, I think we should play with Scrabble rules: no proper names. Finally, there is an example that will really blow your minds: phthalate. The ph- is silent.

[EX Q]: This is something I always get confuse with (native language German). As far as I know 'did + verb' is something done and finished in the past. But isn't it the same with 'verb + ed'?.
[EX A]:
The normal way of talking about something in the past tense is to use 'verb + ed'. For example, 'I finished the project on time'. You might use 'did + verb' if you wanted to emphasise the point. In the previous example, if someone claimed that you completed the project late, you might say 'I did finish the project on time, and here's the evidence'. Using 'did + verb' where there is no doubt about the truth sounds strange to native English speakers. Saying something like 'I did go shopping for food yesterday' will probably lead to the response 'Well nobody said you didn't!'