Learn Swedish: Barnet hade feber på morgonen. - The child had a fever in the morning.

Yes! hade means "had". And remember the golden rule of Swedish verbs: they never change based on the subject. So whether it's "I had" (jag hade), "we had" (vi hade), or "the child had" (barnet hade), the verb stays exactly the same.

The English translation says "a fever", but I don't see en or ett before feber. Why?

In Swedish, you generally don't use "a" or "an" (en or ett) when talking about common illnesses or conditions. While in English you say "I have a fever", in Swedish you just say "I have fever" (Jag har feber or, in this case, Barnet hade feber).

Why is it på morgonen for "in the morning"?

To express "in the morning" referring to a specific morning or a general time of day, Swedish uses the preposition på (on) followed by the definite form of the noun, morgonen (the morning). It literally translates to "on the morning".

As a quick refresher, why is "the child" barnet and not barnen?

Barn (child) is an ett-word. To say "the" for a singular ett-word, you add -et to the end, giving us barnet (the child). Barnen is the plural definite form and means "the children"!