What does ga at the very end of a sentence in Japanese mean?

There's no single meaning for "ga" at the very end of a sentence in Japanese. The particle が (ga) marks the grammatical subject of a sentence. However, its appearance at the very end is unusual and likely indicates one of the following:

* Emphasis/Focus: Putting が at the end can strongly emphasize the subject. It's similar to saying "It's *X* that..." in English. The context is crucial here.

* Childish or informal speech: Very young children or people speaking informally might accidentally or intentionally place が at the end of a sentence. It's not grammatically correct, but understandable in context.

* Dialectal variation: Some dialects might allow for this usage, though it's not standard.

* Typo or mishearing: It's possible it's a mistake in writing or transcription.

Example to illustrate emphasis:

Let's say the sentence is: 田中さんが食べました (Tanaka-san ga tabemashita - Tanaka ate).

Putting が at the end, like 田中さんが食べましたが (Tanaka-san ga tabemashita ga), wouldn't fundamentally change the meaning in terms of who ate, but it would strongly emphasize *Tanaka* as the one who ate, perhaps implying someone else might have been expected to.

In short: Without seeing the full sentence and knowing the context (speaker, situation, surrounding sentences), it's impossible to definitively say what "ga" at the end means. It's not standard grammatical usage.