The plateau is not a plateau, it is the shape of the curve

Almost everyone who studies a language for a year reports the same thing: rapid early progress, then a wall. The usual explanations are motivational — you got comfortable, you stopped pushing, you plateaued.

The arithmetic offers a duller explanation that fits better.

The shape

Cambridge English publishes cumulative guided-learning hours for its own exams. Compressed:

Each level costs roughly what all previous levels cost combined. Getting to A2 is 190 hours; getting from A2 to B1 is another 185. The absolute cost per level is flat-ish; the relative progress halves every time.

Our own level factors have the same shape — A1 at 13% of the full figure, A2 at 27%, B1 at 50%, B2 at 73%, C1 at 100% — normalised against the C1 band and checked to land inside Cambridge's published ranges.

Why this feels like a wall

Progress is experienced as a fraction, not as hours.

Month one takes you from nothing to a few phrases. That is an infinite improvement and it feels like it. Month twelve takes you from B1 to slightly-better-B1, which is maybe 8% more capability for exactly the same effort.

The effort per hour has not changed. The visible return has fallen by an order of magnitude, because the denominator grew.

Nothing is wrong at the plateau. The plateau is the curve. It arrives on schedule for everyone, in every language, at every level of discipline, and the people who describe themselves as having "hit a wall" have usually just arrived at the ordinary part.

The second thing happening at the same time

There is a real change in the task, and it compounds the arithmetic.

Below B1 you are acquiring things that can be listed: words, forms, patterns. Above B1 you are acquiring things that cannot: knowing which of three correct sentences a native speaker would actually say, following speech that was not aimed at you, being wrong in ways nobody corrects because they understood you anyway.

That shift is why self-study gets more expensive with level — 1.25× at A1, 1.7× at C1 — and why immersion gets cheaper. The input the upper levels need is unpredictable and corrected, and only some methods supply it.

So the plateau is arithmetic and a genuine change in what would help. Continuing exactly what worked at A2 is the one response that reliably does not work.

What to actually do

Recalculate rather than reinterpret. Convert your study time into hours and check it against what your target costs. Usually the finding is that you are exactly where the numbers say, and that is a much better thing to know than any story about motivation. The calculator does it.

Change the input, not the intensity. More hours of the same activity is the expensive fix. Adding corrected output — a tutor a few times a month, a conversation partner, anything that produces a response to a sentence you invented — is the cheap one, and it targets what actually changed.

Expect C2 to be worse. It is the one level in the table that costs visibly more than everything before it, and it is why most people should stop at B2 and be pleased.

Do not read the plateau as a verdict on you. It is not about age, it is not about talent, and it is not evidence of anything except that you got far enough for the curve to bend.