I found something from
ericsammons.com/blog/2010/09/30/st-jerome-and-the-filioque/
It says -
When translating John 15:26 (“When the Advocate comes whom I will send you from the Father, the Spirit of truth that proceeds from the Father, he will testify to me”), Jerome used the Latin verb procedere to translate the Greek word εκπορευεται (“proceeds from”). This decision is not a bad one, as both mean “proceed” or “come forth from”. However, by the time of Jerome, this Greek word had come to take on a particular meaning in Greek theology – a meaning that was not there originally. It was used to designate the Holy Spirit’s unique mode of proceeding as opposed to the begetting of the Son in the Godhead. But the Latin term had no such meaning in the West; it could be used interchangeably for both processions.
For example, in John 8:42 (”Jesus said to them, “If God were your Father, you would love me, for I came from God and am here; I did not come on my own, but he sent me”) Jerome again uses the Latin verb procedere, yet the Greek term used is εξηλθον, which means “come forth”, but by Jerome’s time was not identical to εκπορευεται. So in the Latin, both the Son’s procession and the Spirit’s procession used the same broad term – procedere – but the Greeks used different terms for them. Both East and West agreed that both processions could not be identical, so in the West there developed an understanding that the Spirit’s procession was “from the Father and the Son“, a development that did not take hold in the East, which saw the begetting of the Son and the generation of the Spirit as distinct even though both were “from the Father.”
It is important to note that there is absolutely nothing wrong with Jerome’s translation; the fact is that the languages are just different and any translation sometimes has to use the best word available even if it is not an exact match. Furthermore, the Greek language, like every language, had developed, so the term εκπορευεται came to have a precise theological meaning in the East which it did not have at the time of the New Testament. Even without Jerome’s translation decisions the debate over the filioque might have erupted, but the human constraints of language surely played their part in this divisive phrase.
St. Jerome, pray for us!
There is more you can read about it on other sites,
I think in the Greek language it seems to mean that the Holy Spirit has two origins or sources
But in Latin it doesnt mean that
And the Latins agree that only the Father is the origin or source
not too sure
Peace