Questions & Answers about Sono così stanco da non connettere più.
Why do we use da non connettere instead of che non connetto?
When the subject of the main clause ('I am so tired') matches the subject of the result clause ('I don't think straight'), Italian strongly prefers the implicit form: da + infinitive. While così stanco che non connetto più isn't strictly wrong, using da is the standard, natural way to phrase this consequence.
Does connettere really translate to 'think straight' here?
Yes, colloquially! Literally meaning 'to connect', Italians often use connettere to describe someone's brain functioning properly. When you are too tired to connettere, your brain is 'offline' and you can't form coherent thoughts or focus.
Where does the negative non go when using this da + infinitive structure?
It goes directly before the infinitive. The pattern is always da + non + infinitive. Because this sentence also uses più (anymore), that piece directly follows the infinitive, creating the sequence da non connettere più.