Dual Japanese Candlestick Patterns:
The engulfing pattern comes in both bullish form when found at the bottom of a down trend and bearish form when found at the top of an up trend. The pattern is created by a large bodied candlestick that typically has a small wick. This candlestick must completley engulf the previous days candle. Take a look at the image below for two examples.
The harami pattern comes in both bullish form when found at the bottom of a down trend and bearish form when found at the top of an up trend. It is created when a large bodied candle is followed with a smaller bodied candle, whos trading range is within the larger bodied candles open and close. Also forming both bullish and bearish patterns.
Tweezer pattern is formed when two identical candles form at the top (bearish) or bottom(bullish) of a trend. The first candle should be in the same direction as the current trend. For example a bullish tweezer would come at the bottom of a trend and the first candle would be a bearish candle followed by a bullish candle.