One of the trickier things about reading Dari is not knowing what a ی suffix means, and how to read it. Depending on context سیبی could mean “an apple” or “apple-y” or it could be introducing a relative clause (“the apple that I ate”). And the pronunciation changes along with the meaning, so you’ve got to understand the sentence if you’re going to read it aloud. How can you figure it out? I’ve made this one-page flow chart, which you can print out and keep with your reading materials.
Although I hope the flow chart will be helpful, it’s almost humorously complex. This highlights one of the interesting things about language, which is that although it’s possible to create these mechanical descriptions of grammar, that’s now how brains actually work. It’s not as though Dari speakers go through this flow chart mentally every time they see this suffix: they read the sentence and understand it immediately, considering all the possibilities at the same time, and discarding the nonsensical ones without a second thought.
Unfortunately if you’re a new reader that’s now how your brain works… yet! When we’re learning languages we need these scaffolding tools to get started. Eventually your brain will start working things out on its own, and you’ll be able to stop thinking about it explicitly. For now, tools like this can help you through it.