These aren't actually phrasal verbs: they're just combinations of verbs and adverbs. 'Wash' means 'wash' and 'away' means 'away' - nothing is changing its meaning and there's no mystery to solve. Let's start by thinking about the meanings of 'away', 'out' and 'off': 'Away' means that it's not here any more. 'Out' means that it's not 'in' something any more. 'Off' means that it's not 'on' something any more. Combining these words with a verb doesn't necessarily change the meaning: even when combined with 'wash', they keep their true meaning. For example: If there's dust on the road, the rain will wash it away ( it'll go somewhere else: into the gutter or a stream). If a coffee stain has sunk into your tablecloth, a good detergent will wash it out (so the stain is gone) If you have make-up on your face, you use a special cleanser to wash it off (so your face is clean). In/out and on/off. Simple as that. Does that make sense?

They are all generally the same. Depending on what you want to say, some will be used in one context but not the other. For example, you will hear "wash away" in regards to something other than ourselves doing the washing. For instance, the ocean will wash away your sand castle, or wash away footprints on the sand. Wash out and wash off are active verbs in that someone such as yourself is doing the washing. Wash away will also be found in songs and poetry often. Like Soundgarden's "Black hole sun, won't you come and wash away the rain?" "Wash away the pain," like this. Wash off is more common than wash out. If you use wash out, you will usually put the noun in the middle. Like "I need to wash the bucket out." But you could also say "I need to wash out this bucket." You wash out something that has an insides. Usually. People used to commonly say they needed to "wash out" their hair, but this is not as common except maybe in hair salons. They will also say "blow out" (for blow dry and style hair) which I think is adapted from the idea of "wash out." Wash off would be most commonly used when people are dirty. "I need to wash off the grime." "Let me wash off this paint."

Hi Olena, these phrasal verbs have multiple meanings and the last 2 can be somehow similar but not the same wash away: to carry (something) away by the movement of water ex The bridge was washed away by flooding last year. 2 : to get rid of,eliminate (something, such as unhappy or unpleasant thoughts) wash out: to wash something quickly, especially the inside of a container or if a substance washes out of cloth, it can be removed by washing wash off:to clean (something) by using water and to be able to be removed or cleaned by washing(make up)