Making claims and suppositions
State claims and assumptions using the verbs twierdzić (to claim) and przypuszczać (to suppose).
Both verbs are typically followed by a subordinate clause starting with że (that). Conjugate the main verb, add a comma, and follow it with a standard sentence.
| Paleontologists claim that this skeleton is a very old fossil. | Paleontolodzy twierdzą, że ten szkielet to bardzo stara skamieniałość. |
| The paleontologist supposes that this dinosaur could run fast. | Paleontolog przypuszcza, że ten dinozaur mógł szybko biegać. |
You can also use the noun twierdzenie (claim) to discuss specific theories.
| This claim about the evolution of feathers is probably true. | To twierdzenie o ewolucji piór jest chyba prawdziwe. |
Expressing doubt with "żeby"
To express skepticism, use wątpić (to doubt). While claims use że, a subordinate clause following wątpić often begins with żeby (that). The verb inside this clause must take a past-tense form—even when referring to a present fact.
| I doubt that this dinosaur had red feathers. | Wątpię, żeby ten dinozaur miał czerwone pióra. |
Notice how żeby pairs with the past-tense verb miał.
| The writer published a new claim about fossils, but researchers doubt that it is true. | Pisarz opublikował nowe twierdzenie o skamieniałościach, ale badacze wątpią, żeby było prawdziwe. |
Debating theories
You can link these verbs to debate complex ideas, like ewolucja (evolution) or why species wyginęły (went extinct).
To say "I doubt it" without repeating the whole clause, use the phrase wątpić w to (to doubt [in] it).
| Some claim that evolution is a myth, but I doubt it. | Niektórzy twierdzą, że ewolucja to mit, ale ja w to wątpię. |
| I rather doubt that dinosaurs went extinct only because of the meteorite. | Raczej wątpię, żeby dinozaury wyginęły tylko przez meteoryt. |
