How to add "able" to a verb in spanish?

How to add "able" to a verb in spanish?
 

Is there any rule to covert a verb to an adjective ending with "able":
Understandable
Lovable

Also how do you say "****able" in spanish? None of the dictionaries translate this word.

Adam

There is always a translation, but sometimes the conversion isn't as straightforward (it all comes out in the wash, since English isn't that straightforward, either).
If your dictionary doesn't provide the adjective form as an entry, you should check out some of the online dictionaries I use. ;)

General rule:
For -ar verbs, substitute -able.
For -er and -ir verbs, substitute -ible.



Welcome to the forums, by the way.

This one is correct but in Argentina we use amable as friendly, kind OR nice. For lovable we would use querible, even if that word is not in the dictionary... yet. xD

comprendible => comprensible

predict = predecir / pronosticar
predictable = predecible / previsible


presume = presumir / suponer

Three examples

1) hacer (do/make), hecho (fact), factible (feasible)
2) reprender (reprehend), reprensible (reprehensible)
3) pensar (think), pensable[concebible] (thinkable), impensable[inconcebible] (unthinkable)

1) few -but important- words are very irregular, as they are:

• in Spanish: words come directly from ancient Italian (wrongly -in my opinion- called "vulgar Latin") so they are what is called palabras patrimoniales, and later the adjectives come by an independent way straight from 1300-1600 Latin.
• in English: words mostly from Germanic origin and a few palabras patrimoniales from old French, and later their adjectives come by an independent way straight from 1300-1600 Latin. Also, similar words with different origins (doable, feasible)

2) a lot of words are very regular, as both the verb and the adjective were taken from Latin in "modern" times.
3) words from different origin but using a suffix: factible (hacer), feasible (made), machbar (mach)

So, not surprisingly, English and Spanish are not Esperanto so there isn't a way to regularly derive such adjectives, and we even have -able and -ible as suffixes in the regular cases. But it's not hard either.

Thanks for the corrections.