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.

Q: Can one use kindness as a synonym for politeness? What's the difference? Where do you draw the line between them?.

A: I think this is a situation in which etymology is revealing. The background of polite, according to the Online Etymology Dictionary, is: mid-13c., from L. politus 'refined, elegant,' lit. 'polished,' pp. of polire 'to polish, to make smooth.' Used literally at first in English; sense of 'elegant, cultured' is first recorded c.1500, that of 'behaving courteously' is 1762. Polite, both in its original literal usage and in its current usage, is more about superficial appearance. To be polite, one need only use polite words and manners. Nothing internal is necessary. The history of kind, on the other hand, is related to internal goodness: 'friendly,' from O.E. gecynde 'natural, native, innate,' originally 'with the feeling of relatives for each other,' from P.Gmc. gakundiz, from kunjan (see kin), with collective prefix ga- and abstract suffix -iz. Sense development from 'with natural feelings,' to 'well-disposed' (c.1300), 'benign, compassionate' (c.1300). Ultimately, politeness tells you little about a person's character; it may be sincere, or it may be highly calculated. Kindness, though, is directly related to a person's character, and is quite difficult to fake.
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Q: What is the shortest comprehensive sentence in English?.

A: 'Go.' The understood subject is 'You'. '[You] go' makes sense to me.
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Q: In the morning of 19 April 2016, Taliban militants attacked a security team. Or On the morning of 19 April 2016, Taliban militants attacked a security team .

A:
'on' is the correct preposition and 'in' is the incorrect one for this case. 'The morning of' functions as an adjectival phrase clarifying the specific time and date 'on 19 April 2016'. 'On' is used because it belongs to the date here, specific part of the day. The normal language constructions would be: on + date (with the year or without it) or day of the week in + morning, afternoon, evening (in the morning, in the evening) But, when we talk about a specific morning, afternoon, or when we describe the part of the day it should be used with on: on the morning of [date], You can't say 'I will see you on the morning' - it's incorrect. In or on? We use in with morning, afternoon, evening and night, but we use on when we talk about a specific morning, afternoon, etc., or when we describe the part of the day.
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