Learn English – say “how many ones” to ask about quantity

Here is how the example sentences are grammatical:

• The old man the boats.
  The old [people] [man/serve on] the boats

• While Anna dressed the baby spit up on the bed.
  While Anna [got] dressed, the baby spit up on the bed.

• The man returned to his house was happy.
  The man [who was returned to his house] was happy.

• Fat people eat accumulates.
  [The fat that people eat] accumulates

• She told me a little white lie will come back to haunt me.
  She told me [that] [a little white lie will come back to haunt me].

• We painted the wall with cracks.
  We painted the wall [that has] cracks.

Example 1 seems to be legitimate Indian English, see

Something which Indian English has that is not found in other varieties of English is the use of only and itself to emphasize time and place. It comes from the Hindi word hi and produces sentences like "I was in Toledo only" and "Can we meet tomorrow itself?"

extract from language in India

More discussion on 'only' in Indian English here Dustin Freeman

Example 2 is probably Indian English too. You could say you are concentrating on that task, if you wanted to be better understood by a foreign audience.

Example 3: either is correct, I would think the 2nd is more colloquial

I don't think you be misunderstood with any of these colloquialisms. To me they are colourful additions to the language