The “bb” contraction in braille

How to recognise it

Dots 2 and 3 — the letter b slid down one row. It shares its cell with the be- prefix, and that pairing is the only thing about it worth memorising: at the front of a word the cell is be-, in the middle it is a doubled b, and English doubles its b almost nowhere except after a short vowel in the middle of a word. Rubber, hobby, ribbon, rabbit. That is very nearly the whole of it.

The same cell says other things

This is what makes the lower signs hard, and it is not a flaw in the code — there are sixty-three possible cells and far more than sixty-three things to write, so the busiest shapes do several jobs. Position is the whole of the distinction: bb is read where the rules below allow it, and one of these everywhere else.

It has to have a letter on each side

Both neighbours must be letters. A lower sign at the start of a word would be indistinguishable from punctuation opening a sentence, and at the end from punctuation closing one, so the rule bars both positions outright rather than asking the reader to guess.

It is the letter b moved down a row

Take the cell for b and slide every dot down one place — dot 1 to dot 2, dot 4 to dot 5 — and you have this sign. Every lower sign in braille is built that way, which is the reason the family is quicker to learn than eight unrelated shapes would be: you already know all of them, one row up. Most punctuation marks come from the same shift.

How often you will meet it

Of the 5,000 most common English words, 3 words use this sign. That is worth knowing before you spend time on it: the eight lower signs are not equally useful, and they range from 150 of those words down to 3. That is few enough to simply list: the table below is not a selection, it is every one of them. Recognise the shape when it appears and spend your practice time elsewhere.

The contraction list ranks the whole of Grade 2 the same way.

Every word that uses it

Every one of these is shorter in Grade 2 than in Grade 1. They were not chosen by hand: each was taken from the reference implementation's own output for the most common English words, and the build checks that this site still writes them the same way.

Words where it is written out instead

These contain the same letters and do not use the sign. Reading why is the fastest way to learn the rule, because each one fails it for a different reason.

Check your own text

Type anything into the translator with Grade 2 selected and this cell will appear wherever the rules allow it. The full contraction list covers the rest of Grade 2, and the practice drill has a contractions mode that offers the cells one dot away from this one as the wrong answers.