[Steve M.]

At the top of your script:

pawn Код:

new talkSentences = -1;

And the timer function:

pawn Код:

forward TaxiTalk(playerid);
public TaxiTalk(playerid)
{
    switch(talkSentences)
    {
        case 0:
        {
            ProxDetector(3.0, playerid, "Taxi Driver says: Haven't I seen you before?", COLOR_GREY, COLOR_GREY, COLOR_GREY, COLOR_GREY, COLOR_GREY);
            talkSentences++;
        }
        case 1:
        {
            ProxDetector(3.0, playerid, "Taxi Driver says: Lovely weather we are having.", COLOR_GREY, COLOR_GREY, COLOR_GREY, COLOR_GREY, COLOR_GREY);
            talkSentences++;
        }
        case 2:
        {
            ProxDetector(3.0, playerid, "Taxi Driver says: You look happy.", COLOR_GREY, COLOR_GREY, COLOR_GREY, COLOR_GREY, COLOR_GREY);
            talkSentences = -1;
        }
    }
    return 1;
}

And one more thing, edit your part where the timer is started like this:

pawn Код:

if(vehicleid == botcar)
    {
        SendClientMessage(playerid, COLOR_GREY, "Taxi Driver says: Welcome to the Taxi mate, please sit back and enjoy the ride.");
        talkSentences = 0;
        SetTimer("TaxiTalk", 60000, true);
    }

And that should do it. Test it and tell me if it works.