to swim
The term 'nuotare' in Italian is used in the same way as 'to swim' in English. You will use it when you talk about the action of moving through water by moving your body. It is also used in different tenses depending on the context.
I like to swim in the sea.
This sentence is expressing personal enjoyment ('Mi piace') of the activity of swimming ('nuotare') in the sea ('nel mare').
You should swim every day to stay fit.
This sentence is giving advice ('Dovresti') to someone to swim ('nuotare') every day ('ogni giorno') in order to keep fit ('per restare in forma').
She knows how to swim very well.
This sentence is stating the ability of a female subject ('Lei sa') to swim very well ('nuotare molto bene').