Well they are considered interchangeable if used properly as an adverb in the first place. Here's a few guidelines (not rules) that I use when choosing the best fitting form:
Examples:
The term 'radical' is oft seen in science and math.
Just use it! Or do you mean, can you use the word beheld in a sentence.
How do you use the word decibel in a sentence?What is decibel used for?
the word rag in a sentence
use the word "an" in a sentence
The term 'radical' is oft seen in science and math.
Cato the Elder's oft-repeated 'and I think Carthage must be destroyed'.
oft is a poetic word
Oft is not a shortened word. Often is a lengthened word. The original word is oft and the form often did not appear until about a century before Shakespeare's day. They are, of course, the same word and mean the same thing.
He would oft apologize for things that were no fault of his own. The fault line often produced violent earthquakes.
One example of a dictionary word ending in "oft" is "aloft," which means at or to a great height.
As we entered the clearing, I beheld the oft vaunted glimpse of the Moon bow.
You can use the word Truss in a sentence like this.
Can you use the word concluding in a sentence? Done.
Just use it! Or do you mean, can you use the word beheld in a sentence.
How do you use the word decibel in a sentence?What is decibel used for?
You can use the word Terrorist in a sentence as " Muslims are not terrorist ".