I don't know if he will come to the party or not. Is this sentence correct? Or should I say: I don't know whether he will come to the party or not. My friend says the first one is wrong but I don't believe her.Thank you. So the explanation would be: Just as Adam didn't know much about his off ox, I don't know much about this man. Still, how does this fit with the way "know someone from something"? Does "I don't know for certain" mean "I am not certain of my knowledge" or "My knowledge is not certain"? I would choose the former, so "I don't know for definite" sounds wrong to me. When I am certain, I am sure, but I am not "definite". On the other hand, something that is certain may be definite, or even a sure thing. I know it's my fault to have introduced you to this "knowing one's onions" expression, but don't use it too much. In particular, we don't usually combine it with "very well", and we generally don't use it negatively. If you don't mind, kindly tell me the meaning of "knowing one's onion". The statement's intended meaning would be much clearer in speech, where a speaker could give a word special emphasis with his tone of voice: I don't know what is right. = I don't know what right is. Without any emphasis, I don't know what is right means, roughly, I don't know which one of the options/choices is right. The negative forms - whichever you choose - don't occur nearly as often as the positive. Did not use to has been in constant use throughout the English-speaking world since about 1675. Did not used to didn't come into common use till the early 20th century - and didn't surpass the traditional form in AmE till the mid-1970s. "Know the reason why" at the end of a sentence is an idiomatic phrase. In this context it means: I'm going to beat him and if I don't, there'll have been a very good reason to stop me from doing so (which I'll find out). If so, I don't know an equally fixed equivalent in English, but one may express the same idea by saying something like: "A woman who first looks down on a man may well end up looking on him with favour" (this does not suggest marriage, however). For the record, disprezzare may be translated in lots of ways depending on the exact context. I don't know of a connection between ياسر and "wealth." The only meanings I am familiar with for the root ي - س - ر are the one described by Whodunit and "left" (as in the direction). Hello everybody! I've read this sentence on the Net, but I don't know if it's correct in "proper" English. The sentence is this: "He was very well impressed with this gorgeous woman" What do you think? Thank you! :)