Present perfect employed with

1. Other present tenses

1.1. With report/comment verbs or phrases:

1.1.1. Guess, Imagine, suppose

1.2. With the phrases

1.2.1. This is / It's/That's the first, second, only, etc. time

1.3. With unusual or unique events (often with a superlative and EVER or NEVER. Past tense is used to refer to dead people

1.3.1. 1986 Those are the most fantastic people I'VE EVER MET

1.4. When commenting on the present results of something in the past.

1.4.1. Usually with appear, seem, sound

2. With Past tenses

2.1. To describe STATES or EVENTS that have CONTINUED since A TIME IN THE PAST

2.1.1. with SINCe,EVER SINCE

2.2. To DESCRIBE LONG-TERM or REPEATED feelings and thoughts about PAST EVENTS.

3. With another Present Perfect

3.1. To DESCRIBE two states that HAVE EXISTED since a time in the PAST

4. With Future Forms

4.1. In time clauses we don't use WILL, but PRESENT PERFECT

4.1.1. After when

4.1.2. As soon as

4.1.3. Until

4.1.4. Before

5. SINCE & YET

5.1. Position and Emphatic uses

5.1.1. I haven't found the chair yet that can match with the rest of my living room

5.1.2. I've yet to find the chair....