The phrase "actually incapable" is correct and usable in written English.
It can be used to emphasize someone's inability to perform a task or function, often in a context where the expectation was otherwise.
Example: "Despite his confidence, he was actually incapable of completing the project on time."
Alternatives: "truly unable" or "genuinely incapable".
On May 6, the defendants traveled to a warehouse in Connecticut to obtain what they believed was a surface-to-air guided-missile system and three improvised explosive devices, all of which were actually incapable of being fired or detonated.
"Hezbollah's intervention in Syria is an Iranian decision, and it's actually incapable of withdrawing from Syria at the moment even if it's targeted at home," he said.
These implicit solvation models were actually incapable of reflecting the solute-solvent interactions on atomic scale, which has an effect of limiting the reliabilities of the calculated molecular solvation free energies.
Many of these traditional CAC schemes are ineffective leading to incorrect request admission when the network is actually incapable of servicing the request or incorrect rejection when there are actually enough resources to service the request.
The earthquake fault considered most likely to bring destruction to the San Francisco Bay area may actually be incapable of generating a large earthquake on its own, scientists say.
In fact, the speaker actually seemed incapable of playing parts of certain songs, which was puzzling to say the least.
Gemma Chan, who may actually be incapable of doing anything wrong, channeled her fashion-forward character in a one-shouldered pink, frilly dress from Oscar de la Renta with a black belt and matching heels.
They may simply be constitutionally incapable (actually, given the presence of John Ashcroft, make that unconstitutionally incapable) of doing what has to be done.
Despite being incapable of actually writing a song himself, Nathan regularly bought out the composer rights for nominal sums and claimed authorship under the name Lois Mann.
For half an hour it appeared as if England were incapable of actually beating Scotland, let alone running up the points required to give themselves a fighting chance of making the Four Nations final.
