It is easy to to accidentally type a word twice and not notice it, particularly if the word is a short one. Common typos of this kind include:
- Absolute duplicates
- a a
Not done - about about (about)
Done - above above (above) Done
- across across (across) Done
- after after (after) Done
- against against (against) Done
- along along (along) Done
- also also (also) Done
- an an (an, and an) Not done
- and and (and, and an) Not done
- are are (are) Done
- around around (around) Done
- at at (at, at a) Not done
- back back (back) Done
- be be (be) Done
- because because (because) Done
- been been (been) Done
- before before (before) Done
- behind behind (behind) Done
- being being (being) Done
- below below (below) Done
- between between (between) Done
- both both (both) Done
- but but (but) Done
- by by (by) Not done
- during during (during) Done
- first first (first)
- for for (for)
- from from (from)
- had had (many false positives; may be correct, see pluperfect. "He had had some juice already".)
- has has (has, has had)
- have have (have)
- he he
- her her
- his his
- if if
- in in (in, in an)
- included included (included)
- including including (including)
- into into (into)
- is is (is, it is)
- it it
- its its (is its, its)
- last last (last)
- most most (most)
- of of (of, off of)
- on on
- only only (only, only on)
- or or (many false positives; generally one of the "or"s is not the conjunction)
- over over (of over, over)
- played played (played)
- she she (she)
- some some (some)
- than than (than)
- that that (many false positives; may be correct. "She knew that that was the case.")
- the the
- their their
- them them (them)
- then then (then)
- there there (there)
- these these (these, these theses)
- they they (they)
- this this (this)
- those those (those)
- through through (through)
- to to (to, to the)
- under under (under)
- until until (until)
- up to up to (up to)
- was was (was)
- we we (we)
- were were (were)
- when when (when)
- where where (where, where there)
- whether whether (whether)
- which which (which, with which)
- while while (while)
- who who (who)
- whom whom (whom)
- whose whose (whose)
- will will (will)
- with with (with, with which)
- would would (would)
- Near duplicates
- a an
- a the
- an a
- an and
- the this
- Other strange couples
- are been
- was been