English is interesting in that we almost have two independent vocabularies. When speaking informally, you tend to use Germanic words more, and when speaking formally, you tend to use Romance words. I'm writing this formally, which is why I'm using words like "speaking" (which comes from Latin) instead of "talking" (which comes from Middle English).

For example, compare "I need to pick up bread from the store when I'm finished." (Romance words, sounds formal) to "I must get bread from the shop when I'm done." (Germanic words, sounds informal). Both mean the same thing, but (ignoring the stiff wording) the first sounds like something you would say to your grandmother, and the second sounds like something you'd say to your pal at the bar.