Here's a breakdown of the pronunciation:
* Je: "zhuh" (like "juh" in "jug" but with a slightly softer "j" sound)
* t'aime: "tem" (like "tame" but with a slightly softer "t" sound)
* de: "duh" (like "the" but with a softer "d" sound)
* tout: "too" (like "too" in "too much" but with a slightly softer "t" sound)
* mon: "mon" (like "mon" in "Monday" but with a slightly softer "n" sound)
* cœur: "kur" (like "cure" but with a softer "c" sound)
Important note: The "t" in "t'aime" is silent because it's followed by a vowel.
You can also say "Je t'aime du fond du cœur" ("zhuh tem du fon du kur") which means "I love you from the bottom of my heart". This phrase is a little more formal than "Je t'aime de tout mon cœur".