Achèvement vs Achievement

Achèvement refers to the completion or culmination of something.
Achievement has a more positive sense of attaining something that was sought after: exploit, réussite, accomplissement.

Actuellement vs Actually

Actuellement means "at the present time," and should be translated as currently or right now. Je travaille actuellement - I am currently working. A related word is actuel, which means present or current: le problème actuel - the current/present problem.
Actually means "in fact" and should be translated as en fait or à vrai dire. Actually, I don't know him - En fait, je ne le connais pas. Actual means real or true, and depending on the context can be translated as réel, véritable, positif, or concret : The actual value - la valeur réelle.

Affaire vs Affair 

Affaire can mean business, matter, deal, transaction, or scandal.
Affair is the equivalent of affaire only in the sense of an event or concern. A love affair is une liaison, une affaire d'amour, or une aventure amoureuse.

Affluence vs Affluence

Une affluence is a crowd of people: Il y avait une affluence attendant à la porte - There were crowds waiting at the door.
Affluence indicates a lot of something (usually wealth): There's an affluence of information here - Il y a une abondance d'information ici. His affluence is obvious - Sa richesse est évidente.

Agenda vs Agenda 

Agenda refers to a datebook.
Agenda means l'ordre du jour or le programme.

Agonie vs Agony

Agonie refers to death pangs or mortal agony, while Agony means severe physical or mental pain, but not necessarily just this side of death: angoisse, supplice.

Aimer vs Aim 

Aimer means to like or to love.
Aim can be a noun - but, visées - or a verb - braquer, pointer, viser.

Amitié vs Amity

Amitié is the generic French word for friendship, while Amity is used more specifically to mean peaceful relations between nations - concorde or bons rapports.

Ancien vs Ancient 

Ancien can mean old in the sense of not young as well as in the sense of former: mon ancien professeur - my old (former) teacher, mon professeur ancien - my old (aged) teacher. Learn more about adjectives.
Ancient means antique or très vieux.

Argument vs Argument 

Argument is a semi-false cognate. It means argument in the sense of a mathematical or philosophical argument. Also: argument massue - sledgehammer blow; argument publicitaire - advertising claim; argument de vente - selling point.
Argument is une discussion, une conversation, un débat, or une dispute.

Assistance vs Assistance

Assistance is a semi-false cognate. It's primary meaning is audience.
Assistance indicates help or aid.

Assister vs Assist

Assister à nearly always means to attend somthing: J'ai assisté à la conférence - I attended (went to) the conference.
Assist means to help or aid someone or something: I assisted the woman into the building - J'ai aidé la dame à entrer l'immeuble.

Assumer vs Assume

Assumer only means to assume in the sense of taking on responsability or assuming control. It also means to hold a job or fulfill a role.
Assume is a semi-false cognate. In addition to assumer, it can also mean supposer or présumer.

Attendre vs Attend

Attendre à means to wait for: Nous avons attendu pendant deux heures - We waited for two hours.
Attend is translated by assister (see above): I attended the conference - J'ai assisté à la conférence.

Audience vs Audience

Audience is a semi-false cognate. In addition to the meaning of the English word, it can signify: Votre audience, s'il vous plaît - Your attention, please. Ce projet a un large audience - This project has a lot of attention. Donner audience à quelqu'un - To meet with / listen to someone. Audience publique - A public meeting.
Audience is a group of spectators or listeners.

Avertissement vs Advertisement 

Avertissement is a warning or caution, from the verb avertir - to warn.
Advertisement is une publicité, une réclame, or un spot publicitaire.

Bail vs Bail

Bail is a lease; the plural is Baux.
Bail is une caution, on bail is sous caution.

Balance vs Balance 

Balance is a pair of scales or weighing machine. It can also refer to a economic balance.
Balance can be all of the above, plus 閝uilibre or aplomb.

Ballot vs Ballot

Ballot means a bundle or package while Ballot refers to a bulletin de vote (the paper upon which one votes) or a scrutin (the method of voting).

Batterie vs Battery

Batterie is a semi-false cognate. It is equivalent to the English word in all senses, but it can also refer to a set of drums or the percussion instruments in a band.
Battery refers to an electrical device that provides power as well as military weapons: a battery of artillery - une batterie de canons.

Blanc vs Blank

Blanc is a semi-false cognate. It is usually the French word for the color white but can in some instances be translated by blank: une feuille blanche - a blank sheet of paper.
Blank is an adjective meaning empty or without markings.

Bond vs Bond 

Bond refers to a leap or jump. Bondir - to jump.
Bond can mean un engagement, une obligation, or un lien. To bond - coller.

Bout vs Bout 

Bout means end, tip, or bit.
Bout refers to une crise (de rheumatisme) or un combat.

Bras vs Bras 

Bras is an arm.
Bras is the plural of bra - soutien-gorge.

Bureau vs Bureau

Bureau is a semi-false cognate. It can refer to a desk or an office, as well as a department: Bureau europ閑n de l'environnement - European Environment Office.
Bureau can also mean a certain department, especially in government. In British English, a bureau has the same sense of desk as in French, but in American English a bureau is a chest of drawers: commode.

Candide vs Candid

Candide means naïve or ingenuous; Candid means open or frank: franc, sincère.

Car vs Car 

Car is most often used as a conjunction: because or for. As a noun, it refers to a coach or bus.
Car is une voiture.

Caractère vs Character

Caractère refers only to the character or temperament of a person or thing: Cette maison a du caractère - This house has character.
Character can mean both nature/temperament as well as a person in a play: Education develops character - L'éducation développe le caractère. Romeo is a famous character - Romeo est un personnage célebre.

Carton vs Carton

Carton is a semi-false cognate. While it can refer to a box, it can also mean simply cardboard. It can also indicate a target, sketch, or card.
Carton can be a pot, carton, boîte, brick, or cartouche.

Case vs Case 

Case is a square or a box (e.g., on a form), a compartment, or a hut.
Case can refer to un cas, un procès, or une valise.

Caution vs Caution

Caution is a financial term; it can mean guarantee, security, bail, or backing.
Caution indicates prudence, circonspection, or avertissement.

Ceinture vs Century 

Ceinture is a belt.
Century is un siècle.

Cent vs Cent 

Cent is the French word for a hundred.
Cent can be figuratively translated by un sou. Literally, it is one hundredth of a dollar.

Chair vs Chair

Chair means flesh.
Chair can be une chaise, un fauteuil (armchair), or un siège (seat).

Charge vs Charge 

Charge as a noun can mean burden, load, cargo, responsibility. The verb charger means to load or to charge. 
Charge the noun can mean inculpation, accusation, or attaque. The verb to charge can mean accuser or faire payer.

Chat vs Chat

Chat is the French word for cat.
Chat is both a noun and a verb: bavarder/bavardage or discuter/discussion.

Chope vs Chop 

Chope is a mug or pint.
Chop can be a noun - une côtelette, un coup - or a verb - trancher, couper, hacher.

Circulation vs Circulation

Circulation is a semi-false cognate. In addition to the circulation of air, water, etc., it can mean traffic.
Circulation means circulation or propagation.

Client vs Client 

Client is a semi-false cognate. In addition to client, it can refer to a customer, patron, or patient.
Client is a client.

Coin vs Coin

Coin refers to a corner in every sense of the English word. It can also be used figuratively to mean area: l'épicier du coin - the local grocer.
Coin is a piece of metal used as money - une pièce de monnaie.

Collège vs College

Collège and lycée both refer to high school: Mon collège a 1 000 élèves - My high school has 1,000 students.
College is translated by université : This college's tuition is very expensive - Les frais de scolarité à cette université sont très élevés.

Combinaison vs Combination

Combinaison is a semi-false cognate. It can refer to a slip, overalls, or a ski-suit.
Combination is equivalent to the French in virtually all senses of the word. In British English, Combination can also refer to un side-car.

Commander vs Command 

Commander is a semi-false cognate. It means to order (a command) as well as to order a meal or goods/services. Une commande is an order.
Command can be translated by commander, ordonner, or exiger. It is also a noun: ordre or commandement.

Comment vs Comment

Comment is an adverb meaning how or what: Comment vas-tu ? - How are you? Comment t'appelles-tu ? - What is your name?
A Comment is une observation or un commentaire.

Commode vs Commode

Commode as an adjective means convenient or handy; as a noun it indicates a chest of drawers. 
Commode rarely means a chest of drawers, in American English it usually refers to a toilet: toilettes or cabinets. In British English, it means a special chair with a hole, under which is a chamber pot (normally used by disabled persons): une chaise percée.

Commodité vs Commodity

Commodité means convenience: les commodités de la vie moderne - the conveniences of modern life.
Commodity refers to a product for trade, goods: produit, article, denrée (latter refers only to food).

Complet vs Complete 

Complet is an adjective: complete, comprehensive, full, total. The feminine form is complète. It is also the noun for a men's suit.
Complete is an adjective: complet, terminé. It is also a verb: compléter, finir, remplir.

Concerner vs Concern(ed) 

Concerner is a semi-false cognate. It means to concern only in the sense of to affect by something: Cela ne vous concerne pas - This doesn't concern/affect you. Thus concerné means affected by, not concerned about something.
Concern is both a noun and a verb. As a verb, it can mean concerner/toucher as well as inquiéter. The noun means rapport, affaire, souci, intérêt, etc.

Concierge vs Concierge 

Concierge is a semi-false cognate. In addition to the concierge of a hotel, it can refer to the caretaker of a building or apartment house.
Concierge is a member of hotel staff.

Concret vs Concrete 

Concret is an adjective which means concrete (in the sense of real/tangible or made of concrete). Feminine version: concrète.
Concrete can be an adjective or a noun: le béton.

Confident vs Confident

Confident is a noun, the French equivalent of confidant - someone you tell all your secrets and private matters.
Confident is an adjective; the French equivalents are confiant, assuré, sûr, and persuadé.

Consumer vs Consume 

Consumer means to consume only as a fire or as ambition consumes.
Consume usually refers to eating or drinking something: consommer.

Contrée vs Country

Contrée refers only to the physical boundaries of a piece of land or a region.
Country can indicate un pays, une patrie, or la campagne. 

Contrôle vs Control

Contrôle is a semi-false cognate. It usually refers to an inspection, verification, or test, but it can in some cases indicate self-control or control of a vehicle.
Control indicates power over someone (including oneself) or something.

Corps vs Corps 

Corps is a semi-false cognate. In addition to a body of people like Corps de la Paix - Peace Corps, corps can mean (human) body or corpse.
Corps refers to un corps of people.

Crayon vs Crayon 

Crayon is a pencil.
Crayon translates as un crayon de couleur. The French language uses this expression for both crayon and colored pencil.

Crise vs Crisis

Crise is a semi-false cognate; it has several meanings in addition to the English sense of crisis: une crise d'asthme- an asthma attack, une crise de colère - a fit of anger, une crise économique - an economic slump.
Crisis refers to an extremely serious event: crisis management - gestion de crise.