"The heavy boy drinks tea."
Translation:De zware jongen drinkt thee.
Where did the second A come from?
The reason for the second A in "zwaar" (heavy) is to make the open A vowel open even though it's not at the end of the syllable. Without it, the A would be closed. E.g., compare with "zwak" (weak). In "zwa-re" there's no reason for an extra A, as the A is at the end of the syllable thus it is open already.