noticing
v.v. becoming aware of something by seeing, hearing, or feeling it. You use this when you pay attention to a detail that you didn't see before.
v. perceiving or becoming aware of something through the senses or mental attention. The present participle form of 'notice', often used in continuous tenses or as a gerund.
I am noticing a strange smell in the kitchen.
After living in the city for a month, she started noticing the subtle differences between the various neighborhoods.
While the casual observer might overlook the slight discoloration of the leaves, a trained botanist is capable of noticing the earliest signs of a fungal infection.
Transitive; takes a direct object or a 'that' clause. When used with a perception verb pattern, it can be followed by an object and a bare infinitive or an -ing form.
I am noticing you are tiredI notice you are tiredWhile 'noticing' is used for a developing awareness, 'notice' in the simple present is preferred for a sudden realization or a state of fact.