Please look at the student mistakes below and do the following:

Identify what is wrong with the sentence
Write what probably caused the mistake
Identify what type of a mistake it is
Write how you would correct it.
(Note: These are all spoken mistakes. The level of the learner is written next to the sentence).

For example:

Did you enjoyed your holiday? (Intermediate)

Answer:

The student used the past form of the main verb in the past simple question. It should be 'Did you enjoy your holiday?'
Slip of the tongue
Grammar
Repeat to the point of error emphasising 'did' and pointing backwards to indicate the past. Then repeat 'enjoyed' stressing 'ed' with a questioning look. Wait for the student to self-correct.

I "walked" /w?:kId/ to school today. (Elementary)

Let me make a photo of you. (Intermediate)

He's a friendly girl. (Upper-intermediate)

The people was very kind. (Pre-intermediate)

You'd better not criticise her - she is very sensible to criticism. (Advanced)

Good morning, sir. What's up? (Intermediate)

Tomorrow I go to London. (Beginner)