diff --git a/Packages/vChewing_MainAssembly/Sources/MainAssembly/LangModelManager/LMMgr_UserPhraseStructure.swift b/Packages/vChewing_MainAssembly/Sources/MainAssembly/LangModelManager/LMMgr_UserPhraseStructure.swift
index c35dc8e2..f77b8d7a 100644
--- a/Packages/vChewing_MainAssembly/Sources/MainAssembly/LangModelManager/LMMgr_UserPhraseStructure.swift
+++ b/Packages/vChewing_MainAssembly/Sources/MainAssembly/LangModelManager/LMMgr_UserPhraseStructure.swift
@@ -6,8 +6,10 @@
 // marks, or product names of Contributor, except as required to fulfill notice
 // requirements defined in MIT License.
 
+import CandidateWindow
 import Foundation
 import LangModelAssembly
+import Megrez
 import Shared
 
 // MARK: - 使用者語彙類型定義
@@ -32,6 +34,10 @@ public extension LMMgr {
       !keyArray.isEmpty && keyArray.filter(\.isEmpty).isEmpty && !value.isEmpty
     }
 
+    var isSingleCharReadingPair: Bool {
+      value.count == 1 && keyArray.count == 1 && keyArray.first?.first != "_"
+    }
+
     public var description: String {
       descriptionCells.joined(separator: " ")
     }
@@ -190,3 +196,45 @@ public extension LMMgr {
     }
   }
 }
+
+// MARK: - Weight Suggestions.
+
+public extension LMMgr.UserPhrase {
+  mutating func updateWeight(basedOn action: CandidateContextMenuAction) {
+    weight = suggestNextFreq(for: action)
+  }
+
+  func suggestNextFreq(for action: CandidateContextMenuAction, extreme: Bool = false) -> Double? {
+    var extremeFallbackResult: Double? {
+      switch action {
+      case .toBoost: return nil // 不填寫權重的話，預設權重是 0
+      case .toNerf: return -114.514
+      case .toFilter: return nil
+      }
+    }
+    guard !extreme, isSingleCharReadingPair else { return extremeFallbackResult }
+    let factoryUnigrams = inputMode.langModel.factoryCoreUnigramsFor(key: keyArray.joined(separator: "-"))
+    let currentWeight = weight ?? factoryUnigrams.first { $0.value == value }?.score
+    guard let currentWeight = currentWeight else { return extremeFallbackResult }
+    let factoryScores = factoryUnigrams.map(\.score)
+    var neighborValue: Double?
+    switch action {
+    case .toBoost:
+      neighborValue = currentWeight.findNeighborValue(from: factoryScores, greater: true)
+      if let realNeighborValue = neighborValue {
+        neighborValue = realNeighborValue + 0.0001
+      } else {
+        neighborValue = Swift.min(0, currentWeight + 1)
+      }
+    case .toNerf:
+      neighborValue = currentWeight.findNeighborValue(from: factoryScores, greater: false)
+      if let realNeighborValue = neighborValue {
+        neighborValue = realNeighborValue - 0.0001
+      } else {
+        neighborValue = Swift.max(-114.514, currentWeight - 1)
+      }
+    case .toFilter: return nil
+    }
+    return neighborValue ?? extremeFallbackResult
+  }
+}
diff --git a/Packages/vChewing_MainAssembly/Sources/MainAssembly/SessionController/SessionCtl_Delegates.swift b/Packages/vChewing_MainAssembly/Sources/MainAssembly/SessionController/SessionCtl_Delegates.swift
index a580b594..38ba3e89 100644
--- a/Packages/vChewing_MainAssembly/Sources/MainAssembly/SessionController/SessionCtl_Delegates.swift
+++ b/Packages/vChewing_MainAssembly/Sources/MainAssembly/SessionController/SessionCtl_Delegates.swift
@@ -46,8 +46,11 @@ extension SessionCtl: InputHandlerDelegate {
     var userPhrase = LMMgr.UserPhrase(
       keyArray: kvPair.keyArray, value: kvPair.value, inputMode: inputMode
     )
-    if Self.areWeNerfing { userPhrase.weight = -114.514 }
-    LMMgr.writeUserPhrasesAtOnce(userPhrase, areWeFiltering: addToFilter) {
+    var action = CandidateContextMenuAction.toBoost
+    if Self.areWeNerfing { action = .toNerf }
+    if addToFilter { action = .toFilter }
+    userPhrase.updateWeight(basedOn: action)
+    LMMgr.writeUserPhrasesAtOnce(userPhrase, areWeFiltering: action == .toFilter) {
       succeeded = false
     }
     if !succeeded { return false }
@@ -275,7 +278,7 @@ extension SessionCtl: CtlCandidateDelegate {
     var userPhrase = LMMgr.UserPhrase(
       keyArray: rawPair.keyArray, value: rawPair.value, inputMode: inputMode
     )
-    if action == .toNerf { userPhrase.weight = -114.514 }
+    userPhrase.updateWeight(basedOn: action)
     LMMgr.writeUserPhrasesAtOnce(userPhrase, areWeFiltering: action == .toFilter) {
       succeeded = false
     }
diff --git a/Packages/vChewing_SwiftExtension/Sources/SwiftExtension/SwiftExtension.swift b/Packages/vChewing_SwiftExtension/Sources/SwiftExtension/SwiftExtension.swift
index b994e9d9..587e5ea5 100644
--- a/Packages/vChewing_SwiftExtension/Sources/SwiftExtension/SwiftExtension.swift
+++ b/Packages/vChewing_SwiftExtension/Sources/SwiftExtension/SwiftExtension.swift
@@ -398,3 +398,24 @@ public enum ArrayBuilder<OutputModel> {
     Array(components.joined())
   }
 }
+
+// MARK: - Extending Comparable to let it able to find its neighbor values in any collection.
+
+public extension Comparable {
+  func findNeighborValue(from givenSeq: any Collection<Self>, greater isGreater: Bool) -> Self? {
+    let givenArray: [Self] = isGreater ? Array(givenSeq.sorted()) : Array(givenSeq.sorted().reversed())
+    let givenMap: [Int: Self] = .init(uniqueKeysWithValues: Array(givenArray.enumerated()))
+    var (startID, endID, returnableID) = (0, givenArray.count - 1, -1)
+    func internalCompare(_ lhs: Self, _ rhs: Self) -> Bool { isGreater ? lhs <= rhs : lhs >= rhs }
+    while let startObj = givenMap[startID], let endObj = givenMap[endID], internalCompare(startObj, endObj) {
+      let midID = (startID + endID) / 2
+      if let midObj = givenMap[midID], internalCompare(midObj, self) {
+        startID = midID + 1
+      } else {
+        returnableID = midID
+        endID = midID - 1
+      }
+    }
+    return givenMap[returnableID]
+  }
+}