'I also emphasize' is correct and usable in written English.
You can use this phrase to stress something that you already mentioned. For example, "I want everyone to understand the importance of following safety protocols. I also emphasize that it is important to follow the directions of the supervisor at all times."
I also emphasized that the pleasure and pain of doing paleontological work is that fossil data can be rather hard to quantify, and fossils do not fall into easy categories (like the seemingly straightforward quantitative data that genetic base changes seem to suggest).
In that talk on war I also emphasized the need to take care of our own.
"But I also emphasized to my friends that we have to deter a continuing influx of children putting themselves at risk".
I would also emphasize, as Dr. Pardi herself no doubt would have, that, unlike hospice, optimal palliative care can, and should, be provided along with aggressive therapies.
Because of my hardships, I can also emphasize with my staff.
I would also emphasize the coordination required to tackle global humanitarian crises — whether it is epidemics, natural disasters, or famines.
I should also emphasize that my publisher and editors, Eric Vieljeux and Patrice Carrer, were not only generous financially but more importantly with their time, energy, encouragement, and thoughtfulness.
I shall also emphasize what is unknown, concluding with issues of long-term benefits and risks that may ultimately be far more important than the immediate benefit/risk ratio.
I have also emphasized the importance of narrative and remembrance, of the retrospective articulation of the meaning of action by means of storytelling and its preservation through a community of memory.
I also have emphasized that this mentality is part of human nature and will not disappear any time soon.
