'How come' is common and grammatically correct English, but it is not proper English. In fact, “how come” is a colloquialism and has a slightly different use than “why.”
The Merriam-Webster Learner's Dictionary says “how come” is “used to ask why something has happened or is true.” It is a short form of “how did it come about that.” The dictionary also says the expression is usually found in the United States and is used in casual speech.
Americans started using the phrase "how come" in the mid-1800s. It comes from older phrases such as "how comes it that...?" Although the word "how" has had a sense of "why" in its meaning for hundreds of years, "how come" is still considered to be more informal than "why."
used to ask about the reason for something: So how come you got an invitation and not me? "I don't think I'll be able to go swimming tomorrow." "How come?"
It's believed that idioms were first used in oral tradition before being written down. This is because they often rely on wordplay or other linguistic devices that can be lost in translation when they're written down.
In How are you?, how is not a noun phrase, and so cannot function as subject. The sentence is inverted (as is usual in questions in English), and the subject is you, following the verb. Compare What do you want?, where what is not the subject, so the verb do agrees with the subject you, which follows it.
What is the difference between how come and how so?
"how come" is more like "why" and "how so" is more like "in what way" these are really similar, I think in a lot of cases they are interchangeable but there are some times when they aren't. “How come” is also very informal, a replacement for “why.” “How so” is pretty formal, though still mostly a spoken phrase.
The verb "to come" in English is a verb common verb. It has an irregular conjugation. The infinitive is "to come". The base verb is "come". The past simple form is "came".
“This is she” is grammatically correct. The verb “to be” acts as a linking verb, equating subject and object. So this is she and she is this; “she” and “this” are one and the same, interchangeable, and to be truly interchangeable they must both play the same grammatical role—that of the subject.
When to Use Myself and John. You should never use myself and John or John and myself. Both phrases are grammatically incorrect. Instead, use John and me if the speaker is the object of the sentence, and use John and I if the speaker is the subject of the sentence.
Hit the books. Literally, hit the books means to physically hit your reading books, but this phrase is actually used to say that you're going to study. ...
Generally speaking, there are four types of idioms: pure idioms, binomial idioms, partial idioms, and prepositional idioms. Some people may consider clichés, proverbs, and euphemisms to be types of idioms as well, but we'll explain why they are different from idioms.
Again, look at this list of common subordinating words. Used at the beginning of a sentence, these words signal to you that a sentence opener follows: After, Although, As, Because, Before, If, Since, Unless, Until, When, While.
