occurs in long words
portable
No, it is an adjective. It is related to the verb to transport (i.e. transportable).
Prefix=IN
Yes, prefix does have a prefix. The prefix is pur-.
Demi has no prefix; it IS a prefix.
They were highly transportable.
Port
transportable building
Yes they do alright
portable
The storage crate fit Jill's needs perfectly, it was movable between rooms and was transportable to her new house.
Meaning something that can be moved easily.
Yes, transportable wheelchair ramps are actually fairly common. Two large companies that manufacture such ramps are handiramp and literamp.
Apple One.
They were highly transportable.
My read is that portable means you can reasonably expect you can carry it about. Transportable means it is capable of being moved - it is not a fixed/stationary item - but it may or may not exactly be portable.
Transportable Radio Communications (TRC)