Learn
A thousand lessons, and a map of what you actually know
Every course and every lesson is free, from middle school through AP, in four languages and on real CEFR levels.
- lessons, free on every plan
- 1,000+lessons, free on every plan
- courses, Algebra II to Mandarin
- 42courses, Algebra II to Mandarin
- CEFR levels in four languages
- A1 to B2CEFR levels in four languages
Cell Membranes and Transport
Why water moves the way it does
Water does not move toward "more solute" because it is drawn to sugar. It moves because a membrane lets water through while holding solute back, and the two sides settle their water potential.
Water potential has two parts:
- Solute potential falls as solute is added. Pure water sits at 0; every dissolved particle pushes it negative.
- Pressure potential rises when something pushes back, which is exactly what a plant cell wall does.
Water always travels from higher water potential to lower water potential.
A potato core in salt water shrinks. A potato core in distilled water stiffens. Same tissue, opposite gradient.
That single rule covers every tonicity question you will see on the exam. Read the outside solution, compare it to the inside of the cell, and follow the water.
Everything in it
Everything Learn does
The library is the obvious part. Test prep, the skill map, and the language track are the parts people find later and stay for.
The library
Free is not a trial here. The content is free on every plan, permanently.
42 courses
Math, science, English, history, economics, computer science, and sixteen language courses.
Over a thousand lessons
Written for middle school through AP, with the AP courses following the College Board unit order.
Nothing behind a paywall
Every lesson, every course, every level, on the free plan. Paid plans add AI and depth, not content.
Picks up where you left off
Progress is stored per screen, so closing the tab mid-lesson costs you nothing.
How a lesson is built
Screens, not a wall of text you scroll past and forget.
One idea per screen
Concept screens introduce a single thing, so you can tell whether you followed it before moving on.
Worked examples
The full reasoning, step by step, before you are asked to reproduce it.
Checks that are not all multiple choice
Several question types, marked immediately, with an explanation whether you got it right or wrong.
Math and diagrams render properly
Equations are typeset, not screenshots, so they stay readable at any size and in dark mode.
Checks move your mastery
Getting a check right is the same signal as securing a card. One score, two sources.
Languages
Spanish, French, Latin, and Mandarin, on the CEFR scale schools and exams actually use.
Sixteen language courses
Four languages at A1, A2, B1, and B2. Not a gamified ladder with no exit.
A placement test
Start where you are. The CEFR placement test puts you on the right level instead of at lesson one.
Conversation practice
Four modes: open chat, a guided scenario, a structured interview, and a role-play you have to complete.
Fourteen milestones
From your first ten words to finishing B2, marked as you pass them rather than as a progress bar.
Certificates you can verify
Finish a level and get a printable certificate with a code anyone can check. Useful for an application.
Latin, properly
A real Latin track through B2, which almost nothing else outside a textbook offers.
Word Power
Vocabulary through roots and etymology, so one root pays for twenty words.
Five tracks
ACT vocabulary, Spanish roots, Mandarin radicals, Latin roots, and French roots. SAT vocabulary lives inside the SAT track.
Roots, not lists
Every word arrives with its origin and its relatives, which is why the meaning sticks.
It builds you a deck
Words you meet in Word Power turn into a deck in Study, on the same spaced repetition as everything else.
Test prep
SAT and ACT are live, with five AP subjects available.
An adaptive diagnostic
A first sitting that finds your level, then maps every wrong answer to the skill behind it.
Full timed tests
Digital-format practice tests under real timing, section by section, with a test-day mode.
Score history and a prediction
Every sitting is kept and charted, then turned into a predicted score with a confidence band and a percentile.
Accommodations that carry through
Extended time, a dyslexia-friendly typeface, high contrast, color-blind palettes, and larger text, set once.
Review that explains
Go back through a test question by question with the reasoning, not just the correct letter.
Strategies per section
How to handle the question types that cost most students points, written for each section.
A study plan you can follow
Your diagnostic becomes a dated plan in Plan, weighted toward the skills losing you the most points.
A calculator that behaves
A graphing calculator built into the tests that allow one, so nothing has to sit beside your laptop.
A final-week mode
Test-day mode has the checklist, what to expect on the morning, and a reminder that arrives in time.
The skill map
The curriculum as a graph, with your mastery drawn on it.
See the whole subject
A force-directed map of how skills depend on each other, rather than a linear list of chapters.
Your color on the graph
Mastered, learning, and untouched skills are shaded, so the gaps are visible instead of inferred.
Eight domains
Math, reading, writing, science, history, computer science, psychology, and languages, filterable one at a time.
Jump from a gap to the fix
Tap a weak skill and go straight to the lesson or the deck that moves it.
One context
A lesson does not end at the lesson
The reason to learn something inside Slate rather than beside it.
- 01 · Learn
You take the lesson
Concept screens, a worked example, then checks. The checks are marked as you go, with the reasoning.
- 02 · Skill map
The check moves a skill
Each check is tagged to a curriculum skill, so your map updates from the lesson, not from a self-report.
- 03 · Study
The hard parts become cards
Ask the Assistant for a deck on what you just read and it drafts one from that lesson, ready to review.
- 04 · Plan
Review lands on a real day
Those cards get a block in your week, timed to come back before you would have forgotten them.
The check is the point
Reading a lesson tells you it made sense. A check tells you whether you can do it. Slate marks every check immediately, explains the answer either way, and sends the result to the same mastery score your flashcards move.
Cell Membranes and Transport
A plant cell is moved from distilled water into a 0.8 M sucrose solution. What happens to the cell, and why?
What it does not do yet
- Middle school through AP
- The library is written for roughly grade 6 and up. There is one elementary course, a kindergarten math track, and we are not going to call that K-12.
- AP test prep is five subjects
- SAT and ACT are complete. US History, English Language, Biology, Calculus AB, and Psychology have prep today. Five more are listed as coming and marked that way in the app.
- No recorded native audio yet
- Conversation practice uses speech recognition, and Recite listens to you. Recorded native-speaker audio for every lesson is not there yet.
Where a lesson leads
Learn shares one mastery score with Study, so a lesson check and a flashcard are two ways of moving the same number.
Open any course, free
All 42 courses and every lesson are free on every plan, including the four language tracks.