Baba na ya fi ni girma.

Roughly, word by word:

• Baba – father
• na – my (possessive pronoun attached to Baba)
• ya – he (3rd person masculine singular subject pronoun)
• fi – to surpass / to be more than (comparative verb)
• ni – me (1st person singular object pronoun)
• girma – greatness / bigness / seniority (often understood as age or size)

So the structure is like:
Father my he surpass me in greatness/size/age.
Which corresponds to English: My father is older than me.

Yes, literally it is “My father, he…”, and that is normal in Hausa.

Hausa verbs normally need a subject pronoun (ya, ta, na, su, etc.).
When you use a full noun phrase as the subject (like Baba na), it usually comes before the verb, and the subject pronoun still appears before the verb as part of the verbal “slot”.

So the pattern is:

• [Full subject] + [subject pronoun] + [verb] …

Here:

• Baba na – full subject (topic)
• ya – required subject pronoun
• fi – verb

You can’t normally drop ya and just say ✗ Baba na fi ni girma. You need ya there.