A PAIR OF SHOES

One day, just as/when while ('while' has a sense of extended time) Gandhi was stepping up into boarding ('to board' a train, plane, bus, ship...) a train, one of his two shoes suddenly falled fell down onto the rail track road. He couldn’t take it back retrieve it because the train started moving.

All of a sudden, Gandhi slowly ('slowly' is at odds with 'all of a sudden'!) deliberately took off the remaining shoe/sandal one out of his foot and throwed threw it close to/alongside the other shoe in to the surprise of his companion.

When he was asked why he had done so, Gandhi smiled and said: “There will be a certain poor person who finds the shoes on the rail track road and he will have a pair of shoes to wear go.

Tram

After correcting:

A PAIR OF SHOES

One day, just as Gandhi was boarding a train, one of his two shoes suddenly fell down onto the rail track. He couldn’t retrieve it because the train started moving.

All of a sudden, Gandhi deliberately took off the remaining shoe and threw it close to the other shoe to the surprise of his companion.

When he was asked why he had done so, Gandhi smiled and said: “There will be a certain poor person who finds the shoes on the rail track and he will have a pair of shoes to wear.

Thanks!

A PAIR OF SHOES

One day, while Gandhi was stepping up into a train, one of his two shoes suddenly falled down the rail road. He couldn’t take it back because the train started moving.

All of a sudden, Gandhi slowly took the remain one out of his foot and throwed it close to the other shoe in the surprise of his companion.

When he was asked why he had done so, Gandhi smiled and said: “There will be a certain poor person find the shoe on the rail road and he will have a pair of shoes to go.

Tram

...while Gandhi was steping up *onto* a train, of his shoes suddenly *fell off onto the tracks*. ...

...Gandhi slowly took *the shoe off his other foot and threw it close to the other shoe, to the surprise of his companion*. 

*When he was asked why he did that*....*"There will be a certain poor person who finds the shoe on the railroad; now he will have a pair."*