[MINOR][SS][DOCS] Fix a typo in the documentation of GroupState

sql/core/src/main/scala/org/apache/spark/sql/streaming/GroupState.scala

@@ -30,19 +30,19 @@ import org.apache.spark.sql.catalyst.plans.logical.LogicalGroupState
  * --------------------------------------------------------------
  * Both, `mapGroupsWithState` and `flatMapGroupsWithState` in `KeyValueGroupedDataset`
  * will invoke the user-given function on each group (defined by the grouping function in
- * `Dataset.groupByKey()`) while maintaining user-defined per-group state between invocations.
+ * `Dataset.groupByKey()`) while maintaining a user-defined per-group state between invocations.
  * For a static batch Dataset, the function will be invoked once per group. For a streaming
  * Dataset, the function will be invoked for each group repeatedly in every trigger.
  * That is, in every batch of the `StreamingQuery`,
  * the function will be invoked once for each group that has data in the trigger. Furthermore,
- * if timeout is set, then the function will invoked on timed out groups (more detail below).
+ * if timeout is set, then the function will be invoked on timed-out groups (more detail below).
  *
- * The function is invoked with following parameters.
+ * The function is invoked with the following parameters.
  *  - The key of the group.
  *  - An iterator containing all the values for this group.
  *  - A user-defined state object set by previous invocations of the given function.
  *
- * In case of a batch Dataset, there is only one invocation and state object will be empty as
+ * In case of a batch Dataset, there is only one invocation and the state object will be empty as
  * there is no prior state. Essentially, for batch Datasets, `[map/flatMap]GroupsWithState`
  * is equivalent to `[map/flatMap]Groups` and any updates to the state and/or timeouts have
  * no effect.
@@ -85,31 +85,31 @@ import org.apache.spark.sql.catalyst.plans.logical.LogicalGroupState
  *  - With `ProcessingTimeTimeout`, the timeout duration can be set by calling
  *    `GroupState.setTimeoutDuration`. The timeout will occur when the clock has advanced by the set
  *    duration. Guarantees provided by this timeout with a duration of D ms are as follows:
- *    - Timeout will never be occur before the clock time has advanced by D ms
+ *    - Timeout will never occur before the clock time has advanced by D ms
  *    - Timeout will occur eventually when there is a trigger in the query
- *      (i.e. after D ms). So there is a no strict upper bound on when the timeout would occur.
+ *      (i.e. after D ms). So there is no strict upper bound on when the timeout would occur.
  *      For example, the trigger interval of the query will affect when the timeout actually occurs.
- *      If there is no data in the stream (for any group) for a while, then their will not be
+ *      If there is no data in the stream (for any group) for a while, then there will not be
  *      any trigger and timeout function call will not occur until there is data.
  *    - Since the processing time timeout is based on the clock time, it is affected by the
  *      variations in the system clock (i.e. time zone changes, clock skew, etc.).
  *  - With `EventTimeTimeout`, the user also has to specify the event time watermark in
  *    the query using `Dataset.withWatermark()`. With this setting, data that is older than the
- *    watermark are filtered out. The timeout can be set for a group by setting a timeout timestamp
+ *    watermark is filtered out. The timeout can be set for a group by setting a timeout timestamp
  *    using`GroupState.setTimeoutTimestamp()`, and the timeout would occur when the watermark
  *    advances beyond the set timestamp. You can control the timeout delay by two parameters -
  *    (i) watermark delay and an additional duration beyond the timestamp in the event (which
  *    is guaranteed to be newer than watermark due to the filtering). Guarantees provided by this
  *    timeout are as follows:
- *    - Timeout will never be occur before watermark has exceeded the set timeout.
- *    - Similar to processing time timeouts, there is a no strict upper bound on the delay when
+ *    - Timeout will never occur before the watermark has exceeded the set timeout.
+ *    - Similar to processing time timeouts, there is no strict upper bound on the delay when
  *      the timeout actually occurs. The watermark can advance only when there is data in the
- *      stream, and the event time of the data has actually advanced.
+ *      stream and the event time of the data has actually advanced.
  *  - When the timeout occurs for a group, the function is called for that group with no values, and
  *    `GroupState.hasTimedOut()` set to true.
  *  - The timeout is reset every time the function is called on a group, that is,
  *    when the group has new data, or the group has timed out. So the user has to set the timeout
- *    duration every time the function is called, otherwise there will not be any timeout set.
+ *    duration every time the function is called, otherwise, there will not be any timeout set.
  *
  * Scala example of using GroupState in `mapGroupsWithState`:
  * {{{