The word "soldier" is pronounced as: /ˈsoʊl.dʒɚ/ Here’s how to say it step-by-step:

• "sol" sounds like "sole" (rhymes with "goal")
• "dier" sounds like "jer" with a soft "j" sound, like in "judge"

Put together, it sounds like: "SOLE-jer" If you want, I can also provide an audio pronunciation or phonetic spelling in another system!