The US Foreign Service Institute puts full professional proficiency in Mandarin at around 2,200 hours of study, the most for any language they teach. Functional fluency is a lower bar: comfortable everyday conversation, about level 2 on the ILR scale. This app targets roughly 900 hours of focused practice to reach it.

The Cockpit counts toward that number using the hours you actually practice. The count moves only while you're drilling or reading, so it reflects time on task rather than time with the app open. There's no fluency percentage and no daily streak, because neither one tells you how much Mandarin you can use.

Every word you learn is tracked on a review schedule. When you get a word right, the time until its next review gets longer. When you miss it, the word comes back sooner. The aim is to see each word again just before you'd forget it, which builds long-term memory with far fewer reviews than going over everything on a fixed cycle. Today's run is assembled from the words that are due.

Each run mixes short drills, one item at a time:

The Reading tab shows real example sentences, ordered by how many of their characters you already know. Sentences you can fully read come first, then ones with a character or two that are new. The idea, from second-language research, is that you learn most from material you can nearly understand: familiar enough to follow, with a little that's new to stretch you. As your vocabulary grows, more sentences open up.

When you set a goal, every word and sentence is tagged by topic and situation, and the ones that fit your goal are weighted up. For You ranks words on three factors: how common the word is, how it fits your current level, and how well it matches your goal. Your goal also shifts the order of the Reading sentences.

The Balance setting decides how much of that ranking comes from your goal versus broad, high-frequency words that are useful no matter what you're learning for.