No. In Hausa, yana does not mean he only. It is a masculine singular agreement form, so it can refer to:
Here it agrees with bege, which is an abstract noun.
Not in the same way English strong is. Ƙarfi is basically a noun meaning strength. Hausa often uses da + noun to express a quality, so:
Because Hausa does not always use a direct equivalent of English is in the same way English does. In this sentence, the idea of predication is carried by the agreement marker plus da:
So you should think of the whole pattern as the Hausa way to say is strong, rather than trying to match each English word one by one.
You would say:
Begenta ba shi da ƙarfi.
In this pattern, the negative for a masculine singular subject is ba shi da .... So: