A method comprising: at an electronic device having one or more processors, a touch sensitive surface, and a display: displaying a user input interface on the display including a message area and a stroke input area; receiving on the touch sensitive surface in the stroke input area, a first stroke; in response to receiving the first stroke: determining a first character based on the first stroke; and displaying the first character in a message area; at a first time after receiving the first stroke, receiving on the touch sensitive surface a second stroke, wherein the second stroke is distinct from the first stroke; determining whether the first time exceeds a threshold time; in accordance with a determination that the first time exceeds the threshold time, determining a second character based on the second stroke and not based on the first stroke; and displaying the second character in the message area; and; in accordance with a determination that the first time is less than the threshold time: determining a revised first character based on the first stroke and the second stroke; and replacing display of the first character with the revised first character in the message area. at an electronic device having one or more processors, a touch sensitive surface, and a display: displaying a user input interface on the display including a message area and a stroke input area; receiving on the touch sensitive surface in the stroke input area, a first stroke; in response to receiving the first stroke: determining a first character based on the first stroke; and displaying the first character in a message area; at a first time after receiving the first stroke, receiving on the touch sensitive surface a second stroke, wherein the second stroke is distinct from the first stroke; determining whether the first time exceeds a threshold time; in accordance with a determination that the first time exceeds the threshold time, determining a second character based on the second stroke and not based on the first stroke; and displaying the second character in the message area; and; in accordance with a determination that the first time is less than the threshold time: displaying a user input interface on the display including a message area and a stroke input area; receiving on the touch sensitive surface in the stroke input area, a first stroke; in response to receiving the first stroke: determining a first character based on the first stroke; and displaying the first character in a message area; determining a first character based on the first stroke; and displaying the first character in a message area; at a first time after receiving the first stroke, receiving on the touch sensitive surface a second stroke, wherein the second stroke is distinct from the first stroke; determining whether the first time exceeds a threshold time; in accordance with a determination that the first time exceeds the threshold time, determining a second character based on the second stroke and not based on the first stroke; and displaying the second character in the message area; and; in accordance with a determination that the first time is less than the threshold time: determining a revised first character based on the first stroke and the second stroke; and replacing display of the first character with the revised first character in the message area.