Structure of English verbs
Liza Serbaevaにより
1. Simple
1.1. walk
1.2. play
1.3. eat
2. Complex
2.1. underline
2.2. whitewash
3. Phrasal
3.1. look out
3.2. stand up
4. Derived
4.1. unleash
4.2. reread
4.3. replay
5. Semantic
5.1. work
5.2. stay
5.3. go
6. Service
6.1. modal
6.1.1. can
6.1.2. may
6.1.3. must
6.1.4. ought to
6.1.5. need
6.2. auxiliary
6.2.1. to be
6.2.2. to do
6.2.3. will
6.2.4. to have
6.2.5. shall