1. They were sitting around the table.

2. They were sitting round the table.

3. The man turned around and looked at us.
4. The man turned round and looked at us.

[Can we use both 'around' and 'round' in the sentences?]

no first one and third one is true

Hammaad is right. 1 and 3 are best. The word is "around". When people say, as they do, 'round the table, they are merely eliding (skipping) the "a". It's very, very casual and sloppy.

Yes, both "around" and "round" can be used in the sentences you provided. However, there is a slight difference in meaning and usage.

1. "They were sitting around the table": This sentence indicates that the people were sitting near or beside the table, without specifically implying movement or circling the table.

2. "They were sitting round the table": This sentence also means that the people were sitting near or beside the table, but it suggests a circular movement or arrangement, as if they were sitting in a circle around the table.

3. "The man turned around and looked at us": This sentence implies that the man physically turned his body to face in the opposite direction before looking at "us." In this context, "around" indicates a literal change in direction.

4. "The man turned round and looked at us": This sentence also means that the man changed his direction, but it implies a quicker, more casual turn. "Round" suggests a less precise or deliberate movement.

In summary, both "around" and "round" can be used, but they convey slightly different nuances in meaning and usage. The choice depends on the specific context and the desired emphasis on movement or arrangement.