Learn Hardcore Russian: Мёд и лимон помогают при простуде.

The subject мёд и лимон is a compound subject—two singular nouns joined by и—so the verb agrees in number and becomes plural. In other words, “honey and lemon” = “they,” hence пomогают (они помогают).

What case is простуде, and why do we use при here?

простуде is in the prepositional case. The preposition при + prepositional expresses “in the case of” or “when you have” a cold. It indicates the circumstance under which something works.

Could we use с простудой or a dative form instead of при простуде?

You can say с простудой (instrumental) to mean “with a cold,” but it’s less idiomatic for remedies. при простуде is standard to describe a remedy’s condition of use (“when you have a cold”). You cannot say помогают простуде (dative) because that would literally mean “they help the cold itself,” which is not the intended meaning.

What is the nuance of помогают in this sentence? Isn’t помогать “to help someone”?

Here помогают means “to be effective” or “to work,” not literally “to help the cold.” It means “honey and lemon are useful when you have a cold,” rather than “they help the cold.”

How do you pronounce мёд, and why is there ё instead of е?

мёд is pronounced [mʲot], with stress on ё sounding like “yo.” In Russian, ё always indicates this sound and carries the stress. In many texts ё is written as е, so you must know from context that it’s actually мёд, not мед.

Why are there no articles like “a” or “the” before мёд and лимон?

Russian has no articles. Nouns stand alone, and context (and word order) tells you whether you mean something general or specific.

Can you swap the order to лимон и мёд помогают при простуде? Does it change the meaning?

Yes, you can say лимон и мёд помогают при простуде without changing the core meaning. Word order is fairly flexible; swapping them just shifts the emphasis slightly to whichever comes first.