For the "we" form, -er verbs take -emos and -ir verbs take -imos. This is the only time in the entire Spanish language that these two behave differently. Everywhere else they are one group.
-ar → -amos · -er → -emos · -ir → -imos
This is also the first time the i of -ir shows up in the endings at all in the present tense.
Prefiero · Prefiere · Prefieren · but preferimos, with no split
Asked for he lives, the student offers "veve", changing the start of the word to match the ending. Vowel harmony again.
vivir → strip to viv- → add -e → vive
Do not be afraid to try the soft b. If it is too hard, pronouncing /v/ is not a problem, and you might start with /v/ at the beginning and see what happens.
The point is practical: if you program your mind with verano for summer, you may not recognise it when you hear /berano/. So open up the association of the letter v to include that soft b.
Careful with saber: that is a b, so do not pronounce a v there.
Aquí is used in Spain and acá in Latin America. Everybody understands both, and it is such a common word that you need not worry about which you pick.
Vivir is the word in viva la revolución and viva Las Vegas, meaning "long live".
Vivo aquí · No vivo aquí · Vive aquí · Viven aquí · ¿Dónde viven? · Quiero saber dónde viven
When you are drawing a contrast, that is exactly where the word for the person earns its place.
No vivo aquí, pero él vive aquí.
Siempre perdemos, or perdemos siempre. Siempre can go before or after.
The same discipline as before, now with the fuller verb set available.
Entiendo · Entiende · No entiende · ¿Por qué no entiende? · Quiero saber por qué no entiende
Each step adds one block. Nothing in that final sentence had to be known as a whole.