Count to 20 with Words!

Python 2, 145 bytes

print'i am now tiny @ @s##s#ed#act#acts#@#@s#@ed#@ing#arguments#accusation#accusations#advertisings'.replace('#',' counter').replace('@','check')

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Prints these words, separated by spaces:

i
am
now
tiny
check
checks
counter
counters
countered
counteract
counteracts
countercheck
counterchecks
counterchecked
counterchecking
counterarguments
counteraccusation
counteraccusations
counteradvertisings

Jelly,  49 35 31  30 bytes

ṫ3,⁸Ṗ,$€ẎK
“¤ƈȮⱮ⁴⁷ọḤƁŒ|⁾Ė»ḲÇ€K

A niladic link returning a list of characters, or a full program printing that list as a string (the words delimited by spaces).

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How?

ṫ3,⁸Ṗ,$€ẎK - Helper link: list of characters, word    e.g. "abreacts"
ṫ3         - tail word from index 3                          "reacts"
   ⁸       - chain's left argument, word
  ,        - pair                               ["reacts","abreacts"]
      $€   - last two links as a monad for €ach of the two words:
    Ṗ      -   pop (all but last character)      "react" / "abreact"
     ,     -   pair       ["react","reacts"] / ["abreact","abreacts"]
        Ẏ  - tighten          ["react","reacts","abreact","abreacts"]
         K - join with spaces         "react reacts abreact abreacts"

“¤ƈȮⱮ⁴⁷ọḤƁŒ|⁾Ė»ḲÇ€K - Link: no arguments
“¤ƈȮⱮ⁴⁷ọḤƁŒ|⁾Ė»     - a compressed string using dictionary indexes:
                    -   "agar abreacts acknowledges codeterminations deindustrializations"
               Ḳ    - split at spaces
                Ç€  - call the last link (Helper) as a monad for €ach
                  K - join with spaces

...which yields:

a ar aga agar react reacts abreact abreacts knowledge knowledges acknowledge acknowledges determination determinations codetermination codeterminations industrialization industrializations deindustrialization deindustrializations

---

Previous:

@35:

“¡Ụıƭz Xj]"Ɱ*AJƤʂạ5ƬṚṪð^ƥỤ»ḲṖ,$€K€K

Using 10 words and their length-1 prefixes.

@49

“ḊAḥTz¹ỴH¡ṛYẈDƤNŀt#ñ²ĿĊḤlṪnð⁻U+ɦỴĊypṆQ0⁴ṄẉṂi⁻d¤&»

Simply 20 compressed words.

PowerShell, 166 163 bytes

'a
an
and'
'','s','le','ler','lers'|%{"hand$_"}
($a="character")
($x=-split"s ed ful ized istic istics ization izations istically ologically"|%{"$a$_"})
"un"+$x[8]

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Hand-optimized, no algorithms. The two loops |%{ } tack on the appropriate ending to the appropriate beginning. I'm searching for a way to get them down into one loop.