Yes, the two past tenses of "swim" are "swum" and "swam".
Acutally, it is an intransitive verb which needs a 'helping verb' such as have.......... A sentence using the word 'swum' could be: "I've swum to the island every day." The "'ve" stands for "have," a helping verb
I have swum.
Four
will have swum
It must be used after some form of have. He/she/it (has) swum. We/You/they (have) swum. Or having, as in: Having swum the length of the pool....
swum as in I have swum the channel
will have swum is the verb phrase.
It isn't even a word, but swam is. swam is also a verb.
Swum is the past participle of the verb "swim".
swum as in I have swum the channel
"You have just swum" is correct. "Swam" is the past tense, while "swum" is the past participle form of the verb "swim."