Not all can do that.People who have the feelings can understand it.

Its said that "love cannot be hide" so its obvious sooner or later we come to know that a person is in love

This is not possible in all cases but some cases.

Yes character means the things which they perform daily. They dont eat they will stay in other world which is for only love.

Not only in dreams but also in real. They feel that they are sailing in air.

hmm Sandhya, In most of the cases we can identify easily. there are very rare cases who hide their thoughts and control them. They never be transparent.

I used to work in a company. after leaving the company, i met a colleague online. He always used to chat with me in depressed mode and very distress thoughts.Then i felt may be he is in love. and i asked him who is that girl. He said great without see me you found me. and he show his lovers picture. and i gave him few advice to get good answer from her and their engagement is over and they are waiting for their marriage.

Yes we can identify. They will sometimes laugh themselves. They will be so happy for all the time.