The MBTI indicator was first made in order to type ourselves. But it is a fun game, to try and type other people. Or maybe you want to communicate better with a person and simply trying to guess a type will make the communication better.
Introversion vs. Extroversion
The introverted people tend to not think out loud. They usually pause and then answer. That can make them excluded from the conversation, if there are a lot of extroverts in it. Because they usually think out loud. They answer immediately and sometimes they only have a clear thought, after saying it outloud. The extroverts also then do mimic the outer world more than introverts.
Intuition vs. Sensing
If a person is a sensing type, they tend to use their past and present experience to talk. On the other hand, intuition types think about the future and the possibilities, making their talk not focused on the now so much. The sensing types also tend to describe thing is a objective manner; the colour, the sound, the shape and so one. The intuition type of people usually associate the thing with something and they tend to at least imply it.
Feeling vs. Thinking
When talking with the person, do they tend to think in a way, that bring harmony or in a logical way. For example, a person who expresses their worries about others first tend to be feeling types. The people, that express the logic of the situation and the cause-effect chains then to be thinking types. That also apply to the arguments. If a person uses values of people then they tend to be feeling type, while the thinking types usually use argument, that are more connected to logic.
Perceiving vs. Judging
The judging people are the ones, that a person can count on. They tend to do the thing on time and plan ahead. On the other hand, the perceiving type can change their mind and might not be as reliable as the judging type. They are the ones, that go with the flow and change direction as they find it fit. On the other hand, the judging type tend to make order, and tries to stick to that order, no matter the outer world. The perceiving types appear relaxed and do not get stressed by changed, while the judging types are the ordered, reliable ones, that can achieve anything that they start doing it.
There are just some indicators, but the fun is, that you can never be 100% sure of a persons type simply from his behavior. Making a educational guess is possible, and just thinking about the person, even if getting the type wrong, can improve communication.