✅ Summary Group Most Natural Sentences A “A good rest is what you need most.” / “What you most need is a good rest.” B “It was my uncle who telephoned.” / “The person who telephoned is my uncle.”

I agree with Caroline that for A, 4 and 5 sound best. For B, 1, 3 and 4 make grammatical sense. Purely grammatically, 5, 6 and 7 are possible (although it's rather unnatural to use the verb 'telephoning' rather than 'phoning'; or you might say 'on the phone'). Using the past continuous form could suggest phoning over a period of time (for instance, every day). 7 could imply the uncle is now deceased or no longer your uncle for some reason. :)

B. “My uncle” – tense and structure Let’s review each sentence in context. Suppose we’re identifying who telephoned. 1️⃣ My uncle telephoned. ✅ → Simple past, completely correct. 2️⃣ Who telephoned is my uncle. ✅ → Grammatically correct, though slightly unnatural. Normally we’d say: → “It was my uncle who telephoned.” 3️⃣ The person who telephoned is my uncle. ✅ → Correct, natural, present tense for identification. 4️⃣ The man who telephoned is my uncle. ✅ → Also correct and natural. 5️⃣ The man who is telephoning is my uncle. ✅ → Correct only if the call is happening right now. 6️⃣ The man who was telephoning is my uncle. ✅ → Correct if you’re describing something that was happening at some past moment. 7️⃣ The man who was telephoning was my uncle. ✅ → Grammatically correct, but clumsy unless you need both verbs in past tense for narrative consistency. 8️⃣ The person who telephoned has been my uncle. ❌ → Incorrect meaning — has been implies he used to be your uncle but maybe isn’t anymore. ✅ Best choices: → “It was my uncle who telephoned.” (most natural) → or “The person who telephoned is my uncle.”

A. “most” – position and naturalness You want to say: You need a good rest more than anything else. Let’s see which versions are grammatically correct and idiomatic in English. 1️⃣ You need a good rest most. ❌ → Not natural. In English, most doesn’t usually come at the end of this sentence. 2️⃣ You most need a good rest. ✅ → Grammatically correct and clear, but sounds a bit formal or literary. 3️⃣ You need most a good rest. ❌ → Incorrect word order — sounds unnatural. 4️⃣ A good rest is what you need most. ✅⭐ → Perfectly natural, idiomatic, and the best choice. 5️⃣ What you most need is a good rest. ✅ → Also correct and slightly more formal or elegant. ✅ Best choices: → “A good rest is what you need most.” → “What you most need is a good rest.”

For A, I would use either 4 or 5, but I think 5 sounds better. For B, I think number 1 sounds most natural. Hope that helps!