Some people will say that as long as what you’re saying is understood and interpreted correctly, it really doesn’t matter if what you write is completely grammatically correct. Even so, you still want to know what’s right, don’t you?
Consider these two examples:
There were between 10 and 20 people in attendance.
There were between 10 to 20 people in attendance.
Which one is correct? Whenever you use the “between” construction as shown above, the two numbers that “book-end” the range should be separated by the word “and.” It is always between X and Y, never between X to Y. This is related in some ways to the from-to construction that we discussed earlier this year.
My colleague then brought up the example of time.
The project will take between two and three years to complete.
The project will take between two to three years to complete.
In this instance, it is still correct to use “and” as the word between the two numbers. It doesn’t matter if you’re talking about time or number of objects. So, when should you be using “to” instead? “To” becomes appropriate if there is no “between” preceding the range.
The project will take two to three years to complete.
There were 10 to 20 people in attendance.
The first sentence can alternatively have “from two to three years” if you prefer, but the “from” isn’t really necessary. Just remember that if you’re going to use “between” that you should be using an “and” to separate the two elements, just like how you would say that someone is stuck “between” a rock “and” a hard place.
Yes, good grammar matters, because it reflects on your professionalism and the level of respect that you demand. Even if you don’t write professionally, be careful with your word choice and, when you’re not sure what word to use, ask someone for help! After all, he who asks may be the fool for five minutes, but he who does not ask will look the fool forever.