From what I understood, if I want to talk about my teacher with my friend I have to use the honorific informal form, but how do I create this form? Do I just remove 다 from the verb to then make it become 시다 that conjugated at the informal present becomes 셔. For example 가다 becomes 가셔. And when the root ends with a consonant do I use 으시다 that then becomes 으셔. Is this correct?