Atoms form bonds with other atoms with the purpose of completing their outer energy levels. So a good strategy of predicting how many bonds an atom will form is to first establish how many electrons it needs to complete its valence shell.
F has 7 valence electrons, it needs one more electron to complete its valence shell so it forms one bond
Si has 4 valence electrons, it needs four more so it forms four bonds
O has 6 valence electrons, it needs two more so it forms two bonds
