Getting married in Singapore when one of you is a foreigner
Registering a marriage means proving two things: who you are, and that you are free to marry. Where the documents proving either are not in English, they are read in translation, and the registry is checking that they agree with one another.
Proving who you are
Identity documents and birth certificates carry the names, dates and places that everything else is checked against. If a passport is bilingual, it may not need translating at all, which is worth confirming before ordering.
Where a name appears differently across documents, and it very often does, the set has to explain itself rather than leave the registry to guess. Following the passport spelling and noting the variants is what makes a set read as one person.
Proving you are free to marry
Where a previous marriage ended, expect to produce the divorce certificate or the death certificate for the former spouse. These are the documents most often forgotten until late, because they belong to a chapter people have closed.
They are also the ones most likely to be held abroad, in another language, and to take weeks to obtain a certified copy of.
Send the set together
Quoting and translating the documents as one job keeps names, dates and place names consistent across all of them, which is the thing the registry is actually looking at. Sending them one at a time invites exactly the inconsistency that causes a set to be returned.
Confirm the requirement first
What the registry asks for depends on your nationality and your circumstances, and the list changes. Check it with them directly, then translate whatever on that list is not already in English.