diff --git a/entity/event/registry.go b/entity/event/registry.go
index 29797e491..bb69b0916 100644
--- a/entity/event/registry.go
+++ b/entity/event/registry.go
@@ -23,7 +23,7 @@ func (registry *Registry) Register(eventName string, eventVersion int, decoder D
 	registry.decoders[eventType(eventName, eventVersion)] = decoder
 }
 
-// IsRegister returns true when the event to decoder mapping is already registered
+// IsRegistered returns true when the event to decoder mapping is already registered
 func (registry *Registry) IsRegistered(eventName string, eventVersion int) bool {
 	_, exist := registry.decoders[eventType(eventName, eventVersion)]
 	return exist
diff --git a/entity/projection/manager.go b/entity/projection/manager.go
index deefababd..9e389d493 100644
--- a/entity/projection/manager.go
+++ b/entity/projection/manager.go
@@ -84,7 +84,7 @@ func (manager *StoreBasedManager) projectionRunner(projection Projection) {
 	for {
 		latestEventHeight, _ := manager.eventStore.GetLatestHeight()
 		if latestEventHeight == nil {
-			logger.Debugf("no event in in the system yet")
+			logger.Debugf("no event in the system yet")
 			<-waitFor(5 * time.Second)
 			continue
 		}
diff --git a/usecase/coin/dec_coin.go b/usecase/coin/dec_coin.go
index 224bdb805..a10e4c9ee 100644
--- a/usecase/coin/dec_coin.go
+++ b/usecase/coin/dec_coin.go
@@ -634,7 +634,7 @@ func (coins DecCoins) Sort() DecCoins {
 // ----------------------------------------------------------------------------
 // Parsing
 
-// MustParseDecCoins  parses a decimal coin from a string. It behaves the same as ParseDecCoin,
+// MustParseDecCoin parses a decimal coin from a string. It behaves the same as ParseDecCoin,
 // except it panics on any error.
 func MustParseDecCoin(coinStr string) DecCoin {
 	decCoin, err := ParseDecCoin(coinStr)
diff --git a/usecase/coin/uint.go b/usecase/coin/uint.go
index bf1db39b1..a244a4db9 100644
--- a/usecase/coin/uint.go
+++ b/usecase/coin/uint.go
@@ -18,7 +18,7 @@ func (u Uint) BigInt() *big.Int {
 	return new(big.Int).Set(u.i)
 }
 
-// NewUintFromBigUint constructs Uint from big.Uint
+// NewUintFromBigInt constructs Uint from big.Int
 func NewUintFromBigInt(i *big.Int) Uint {
 	u, err := checkNewUint(i)
 	if err != nil {