One-to-one is used when you talk about transfer or communications. You may use one-to-one when you can identify a source and a destination. For eg., a one-to-one email is one sent from a single person to another, i.e., no ccs or bccs.

Understanding the Context

In maths, a one-to-one mapping maps one element of a set to a unique element in a target set. One-on-one is the correct adjective in your example. See Free ... "Which one is the best" is obviously a question format, so it makes sense that " which one the best is " should be the correct form.

Key Insights

This is very good instinct, and you could even argue that the grammar is good, but at best it's unnatural. I want to know what the constraints are on using the phrase one of the. Is it used correctly in this example? He is one of the soldiers who fight for their country. Is the use of "one of the" correct in the following context?

Final Thoughts

Some people say a dog=one, dogs=ones, the dog=the one=that, and the dogs=the ones=those. It's a rule of thumb, but what I found was that this is not always correct. Iโ€™m looking for a word or short phrase that can be used as an adjective to describe a person who does, or the act of doing, something that could match one of the following descriptions: distils co... phrase requests - Is there a word to describe one who distils complex ... Which one is grammatically correct or better? I have two assignments, One of them is done.

I have two assignments, One of which is done. I watched a video tutorial that the teacher said the ...