Present Perfect vs. Past Simple

The Present Perfect and the Past Simple both talk about the past, but we choose between them by looking at time. We use the Present Perfect (have/has + past participle) when an action started in the past and is still true now, or when the exact time is not important because we care about the result. With it we often use "for" and "since": we use "for" with a length of time, like "for three years" or "for two hours", and we use "since" with a point in time, like "since 2019" or "since Monday". We use the Past Simple when the action is completely finished and we know (or say) the exact past time. Words such as "yesterday", "last week", "in 2010", and "two days ago" point to a finished time, so they need the Past Simple. So we say "We have lived here since 2019" (we still live here now) but "We lived in Baku in 2010" (that time is finished). Choosing the right tense means asking: is the time finished, or is the action still connected to now?