From sona pona

    how to know what's a modifier and what's a head, and thus where to put which:

    head· the main idea that you're talking about, and that can't be dropped without changing entirely what you're referring to. in the english phrase "the red dog", you're talking about a dog, and taking it away (the red) changes the meaning entirely

    modifier· the idea that modifies the head to some extent, giving more information that can often be left out. in "my house", the house is what you're talking about, but it being yours gives more information about it

    and from there, you always put the head first, then any modifiers

    leading to soweli loje and tomo sina respectively

    There are no hard-set compound phrases in toki pona. This is by design! Part of the goal of the language is for you to break down your surroundings from your own viewpoint and describe things dynamically, not use the same phrase to mean the same thing all the time. Think about what the topic means to you, and consider what is important about it :)