If an alien lands on Earth and learns English, would you deem it non-intelligent if you can tell it apart from a human in conversation?

I think we should consider slime mold intelligent, and realise that it's a spectrum. Path finding is AI. There are probably forms of intelligence we have yet to discover.

If an alien landed we could decide whether it seems to have a human-like intelligence or not. It could be incredibly intelligent but very non-human-like.