Definitely is saying something with certitude, sort of like something everyone will agree with. „He definitely has an accent when speaking.“ So and so is definitely a nice man. Certainly and surely are very close. I will certainly go if asked. I will surely go if asked. Those two sentences pretty much mean the same thing. I honestly can`t think if a sentence where you couldn`t substitute certainly for surely. „ She surely is crazy“ could also be said „she certainly is crazy.“ You could also use definitely in those two sentences, but the only difference is that definitely seems to put a bit more emphasis on the crazy part a little more. All of the words convey a feeling of people likely to agree with what you are saying, and they can be negative or positive. They’re not just limited to being positive. „She surely is not going to live much longer. After all, she`s 99.“

Definitely and certainly both mean the same. Surely should mean the same, but instead of expressing certainty it is often used to question it: Definitely/certainly this is strange. Surely this is wrong? The meaning of definitely and certainly is consistently positive and confident; the meaning of surely is changed by word order; the following all essentially mean the same: I am definitely right I am certainly right I am surely right Definitely I am right Certainly I am right But this does not: Surely I am right?

The words "surely" and "certainly" are very close in their meaning. Both words are used when there is no doubt. They have their roots in words that mean "secure" and "reliable". A man might say to his girlfriend, "I certainly love you" when he has no doubt. The woman might say, "he surely loves me because he is so thoughtful and kind". The word "definitely", however, has its roots in a word that means specific, precise and exact. If a man says to his wife, "I definitely love you" it will not have the same emotion. Hope this helps

Me: Surely any differences between them will be certainly subtle? Him: Definitely! Me: Surely you are definitely coming to the party? You: Certainly! You would think they are interchangeable perhaps only a linguist would definitely know. You will just have to keep an eye out for usage I would use surely less often than the other two words and in a question. Use them as you will most people won't notice the issues if there are any.

Hey Chris, Thank you for your suggestion! I just edited my question and narrowed down the list of words to 3 (words). So, do you think you could be able to reply to my question now?