WHO AND WHOM
'Who' is a subjective pronoun, along with 'he', 'she', 'it', 'we', and 'they'. It is used when the pronoun acts as the subject of the clause. 'Whom' is a objective pronoun, along with 'him', 'her', 'it', 'us', and 'them'. It is used when the pronun acts as the object of the clause. Using 'who' or 'whom' depends on whether you are referring to the subject or object of a sentences. When in doubt, substitute 'who' with the subjective pronouns 'he', 'she', e.g. Who loves you? He loves me. Similarly, you can also substitute 'whom' with the objective pronounss 'him', 'her', e.g.. I consulted an attorney whom i met in New York. I consulted him.
WHICH AND THAT
'That' is a restrictive pronoun. It is vital to the noun to which it is referring. E.g., i don't trust fruits and vegetables that aren't organic. Here, i am referring to all non-organic fruits and vegetables. In other words i only trust fruits and vegetables that are organic. 'Which' intruduce a relative clause. It allows qualifiers that may not be essential. E.g., i recommend you eat only organic fruits and vegetables, which are available in area grocery stores. In this case you don't need to go to a specific grocery stores to obtain organic fruits and vegetables. 'Which' qualifies, 'that' restrict. 'Which' is more ambiguous however, and by virtue of its meaning is flexible enough to be used in many restrictive clause. E.g., the house, which is burning, is mine. E.g., the house that is urning is mine.
LAY AND LIE
'Lay is a tansitive verb. It requires a direct subject and one or more objects. Its present tense is 'lay', e.g., i lay the pencil on the table; and its past tense is 'laid', e.g., yesterday i laid the pencil on the table. 'Lie' is a intransitive verb. It needs no object. Its present tense is 'lie', e.g., the Andes mountains lie between Chile and Argentina; and its past tense is ;lay', e.g., the man lay waiting for an ambulance. The most common mistakes occurs when the writer uses the past tense of the transitive 'lay', e.g., i laid on the bed; when he/she actually means the intransitive past tense of 'lie', e.g., i lay on the bed.
CONTINUAL AND CONTINUOUS
They are similar but there is a diference. 'Continual' means something that always occuring, with obvious lapses in time. 'Continuous' means something continues without any stops or gaps in between. E.g., the continual music next door made it the worst night of studing ever. E.g., her continuous talking prevented him from concentrating.
ENVY AND JEALOUSY
The word 'envy' implies a longing for someone else's good fortunes. 'Jealousy' is far more nefarious. It is a fear of rivalry, often present in sexual situations. 'Envy' is when you covet your friend's good looks. 'Jealousy' is what happens when your significant other swoons over your good-looking friend.
MAY AND MIGHT
'May' implies a possibility. 'Might' implies far more uncertainity. 'You may get drunk if you have two shots in tem minutes' implies a real possibility of drunkness. 'You might get a ticket if you operate a tug boat while drunk' implies a possiblity that is far more remote. Someone who says 'I may have more wine' could mean he/she doesn't want more wine right now, or that he/she 'might' not want any at all. Given the speaker's indecision on the matter. 'Might' would be correct.
BRING OR TAKE
In order to employ proper usage of 'bring' or 'take', the writer must know whether the object is being moved toward or away from the subject. If it is toward, use 'bring', if it is away, use 'take'. Your spouse may tell you to 'take your clothes to the cleaners'. The owner of the dry cleaners would say 'bring your clothes to the cleaners'.