"I love every weekend."
In English, it's hard to tell whether or not "every weekend" is the object or is a just a 'time phrase' (prepositional phrase?). It feels correct to directly translate it as if "every weekend" were the object, but I wasn't sure whether or not Duo wanted me to follow the placement of the 'time phrase' here.
“love” is a transitive verb, so “every weekend” is the object here. “I love” is not a complete sentence.
Not true, love can be intransitive. See: Merriam-Webster
Example: "Poets should love"
In this case, it's more of an abstract meaning
No, 每個 already means "every one" so adding 都 makes no sense: "I love every all weekend."