What's the best way to tell ESTp from ESFp ( subtype) in a work environment? I think I have to work with a person who is one of those but so far I can't tell which. First I thought ESFp but after a while I started to think perhaps ESTp because of certain things. However I'm still not sure. The person seems very professional but with a playful side too which quickly surfaces in non-professional situations, seems very good with people (especially getting to know new people, I'm not sure about long term contact yet) and kinda "feelery" but also very controlled. Curious fact: the person seems to quickly go from "hot" (meaning smiling and being friendly and informal) to "cold" (meaning being distant and cold and formal) in certain situations. This happens especially when superiors are around or someone need to be impressed etc. or when situation calls for strict professional attitude). Occasionally makes certain "inconsistency errors" even when trying to be very professional. Like using word "summer" when meant to use "spring" and this make the general "professional outlook" lack a bit every now and then (but rarely). Any quick hints to tell the difference? I might be Ni-dominant as I just loved the It might even be dual experience or just dual-seeking experience. The rest of the functions confuse me. ESFp or ESTp?