On p24 in Keller's Learn to Read Latin:
ambulo, ambulire, ambulivi, amhulitum (1-intr.) walk
amo, amare, amavi, amatus (1-tr.) love
cogito (1-tr.) think; ponder
do, dare, dedi, datus give, grant
What does "1" mean in the first three entries of the vocabulary?
Is transitive or intransitive always specified for each verb? Why is it not in the last entry?