Today I reviewed some lessons of in English and ein Spanish. Today I reviewed some lessons in English and in Spanish.

Today I reviewed some lessons of in English and ein Spanish. Today I reviewed some lessons in English and in Spanish.

Today I reviewed some lessons of English and en Spanish. Today I reviewed some lessons of English and Spanish.

Today I reviewed some lessons of in English and ein Spanish. Today I reviewed some lessons in English and in Spanish.

We use "in [language]" to say what languages the materials were in.

Then I read have finished the whole book that I was reading. OR Now I have finished reading an entire book. Then I finished the whole book that I was reading. OR Now I have finished reading an entire book.

Then I read have finished the whole book that I was reading. Then I finished the whole book that I was reading.

Then I read have finished reading the whole book that I was reading. Then I finished reading the whole book that I was reading.

Then I read have finished the wholrest of the book that I was reading. Then I finished the rest of the book that I was reading.

This sounds more natural in the US.