He looks for a job.- What does he look for?
He lookED for a job- What did he look for?
they are thinking about holidays- What are they thinking about?
they thought about holidays- What did they think about?
they are speaking about plans- What are they speaking about?
they spoke about plans- What did they speak about.
she is speaking to teacher- Who is she speaking to?
she spoke to her teacher- Who did she speak to?
she often speaks to her teacher - Who does she often speak to?