What is the past use of swan and present swan?

The word "swan" has a consistent meaning and usage throughout history. There's no distinct "past use" and "present use" like you might find with words that have changed meaning over time.

"Swan" has always referred to the same bird, a large waterbird with a long neck and graceful movements.

Perhaps you're thinking of the different types of swans, which have remained consistent:

* Mute swan: The most common swan in Europe and North America, known for its quiet nature.

* Whooper swan: A large, trumpeting swan found in northern Eurasia and North America.

* Trumpeter swan: The largest North American swan, known for its loud trumpet call.

If you could provide more context about what you're looking for, I might be able to give you a more helpful answer.