変わる
ka-wa-ru
Change with no hand in the picture
The picture Something stays in its place but has crossed over into a different form, with no hand in sight. 変わる has crossed over on its own; 変える is a hand reaching in and making it cross.
Where the picture shows up in 変わる
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A color crossing over
信号が青に変わりました。
shingō ga ao ni kawari-mashita
The light changed to green.
Inside the same lamp the red goes dark, the green comes up, and the road opens.
～に変わる points at the form it has crossed into.
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A fixed thing crossing
来週から時間が変わります。
raishū kara jikan ga kawari-masu
The hours change from next week.
On the shift chart the old number is rubbed out and a new one takes its place.
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A view crossing over
町の様子がすっかり変わりました。
machi no yōsu ga sukkari kawari-mashita
The neighborhood has completely changed.
Back after years, the lane holds unfamiliar buildings and reads as somewhere else.
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A person coming back different
彼は国に帰ってから変わりました。
kare wa kuni ni kaette kara kawari-mashita
He changed after going home for a while.
The same face, but the voice and the walk no longer match the ones you knew.
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Crossing over again and again
ここの天気は変わりやすいです。
koko no tenki wa kawari-yasui desu
The weather here changes easily.
Within an hour clear sky and rain cloud trade places several times.
変わりやすい is the form for 'changes easily'.
All of it in one picture
変わる is one picture: same place, different form. Red crosses to green and the light has changed; the number on the shift chart crosses to another and the hours have changed; the lane crosses into something unrecognizable and the neighborhood has changed; a voice and a walk cross into something new and the person has changed; the sky crosses back and forth and the weather is fickle. The hand that did it never appears in the sentence.